# The official app scores only 2.99 stars, so a Vietnamese developer rebuilt it for owners: ThatBike's playbook is worth copying, but the ceiling is low

> Source: https://stringers.io/en/apps/ios_6823236685.html (Stringers / 什么值得做, generated 2026-11-08)
> Stringers answers one question every day: what small product can one or two people build in a few months and actually make money from. Numbers come from 15 databases we collect daily, each with source and date.
> For agents: these verdicts and the underlying databases (verified revenue, App Store / Google Play charts, ad libraries, GitHub, Product Hunt…) are queryable live over MCP — tools today / hot / products / directions / direction / data. Setup: https://github.com/komako-workshop/stringers (the user logs in at stringers.io → "配置 agent" to get a personal URL). Site index: https://stringers.io/llms.txt

> The official app averages 2.99 stars, drops connections constantly, and needs internet. On Android, DuBike already got owners used to third-party apps, but nobody had built one for iOS. When the author posted in an owners' group, a wave of users showed up.

[Mobile App](https://stringers.io/en/apps/index.md) · iOS · written 11-6

T

ThatBike - Đồng Hành Xe Điện · Tung Nguyen

# The official app scores only 2.99 stars, so a Vietnamese developer rebuilt it for owners: ThatBike's playbook is worth copying, but the ceiling is low

**What it is** An unofficial iPhone app for owners of Dat Bike electric motorcycles in Vietnam. Over Bluetooth it reads the dashboard, shows per-cell battery voltage, and locks, unlocks, and locates the bike. It works offline and needs no sign-up.

**Why it took off** The official app averages 2.99 stars, drops connections constantly, and requires internet. Android already had DuBike, so owners were used to third-party apps, but nobody had built one for iOS. When the developer posted in owner groups, people came in.

**C** **How you could follow it** Don't build another Dat Bike app. Take the approach to another brand: look for hardware where official-app reviews complain about connectivity and offline failures, where owner communities are active. Reverse-engineer the Bluetooth protocol to build an offline client that only does what the official app already does, and cold-start in the community.

Grade C: one brand with a few tens of thousands of owners, the iOS market is already taken by this app, and growth has slowed. Revenue is just tips and a $5.7 theme, and the manufacturer could block it with a firmware update anytime. The method is worth learning, but copying the product isn't. Few people know about it yet

Data (updated daily) · First launched 2026-10-25 · Vietnam rating 28 · Charted in 11-08 of 1 stores

iOS · best category chart rank · by store

Data 2026-10-28 → 2026-11-08 (12 days, 12 observations). Lower rank is higher; gaps mean it wasn't charted that day

iOS · Rating count · Vietnam

Data 2026-10-28 → 2026-11-08 (12 days, 12 observations). Apple doesn't publish download counts; rating growth is a proxy for downloads.

ThatBike is an iPhone app for owners of Vietnam's Dat Bike electric motorcycles. It's unofficial and built by one person. It launched in Oct 25 and collected 28 ratings in 12 days, averaging 4.9 stars. It spent nothing on promotion. The official app was just too hard to use, owners were already waiting for an alternative, and nobody had built one for iOS. The approach could be reused on other hardware, but as far as ThatBike itself goes, one brand has only a few tens of thousands of owners, and a single firmware update from the manufacturer could shut it down.

### "You have to unlock the bike with your card first, then reconnect from scratch"

In Nov 3, a Dat Bike owner gave the official app 2 stars on the App Store: "It connects the first time, but after that it won't reconnect automatically. To use the app to ride, you have to open the bike with your card first and then reconnect from the start. So inconvenient." The day before, another review gave 1 stars: "If you turn off the phone and back on, it won't auto-connect. You have to delete the device and set it up again, and it happens every time."

A week earlier, on Oct 28, in the same store, someone gave ThatBike 5 stars: "Works well, especially since it doesn't drop connections like the official app does. Giving 5 stars for the effort."

The ThatBike story is basically the gap between those two reviews.

### What it is

Dat Bike is a Vietnamese electric motorcycle brand (Quantum, ERA series). The bikes connect to phones over Bluetooth: unlocking, checking battery, and firmware updates all go through the official app. ThatBike does the same job, only better:

- **The iPhone as dashboard** : speed, turn signals, live current, remaining range, motor and battery temperature, with an option to keep the screen on.

- **Battery detail** : per-cell voltage, the gap between the highest and lowest cell, and charge cycle count. One owner 10-27 wrote: "I can see how many times I've charged, and each cell."

- **One-tap control** : lock, unlock, power off, and honk to find the bike, with widgets on the home and lock screens. The lock button is grayed out while the bike is running, to prevent accidental presses.

- **Fully offline** : no account needed, no data uploaded, no location permission, and the pairing key is stored in the iPhone keychain.

- **Look before you buy** : a simulation mode uses fake data so you can walk through every screen without a bike.

It updates fast. In the 10 days after launch it shipped 5 versions. In Nov 4, the 1.5.0 update added an Apple Watch app, Siri shortcuts ("Khoá ThatBike", lock the bike), an alert when charging reaches a set level, and support for older firmware from 1.12.1 (per the App Store release notes).

Neither the app name nor the description ever says "Dat Bike." They only say "compatible with Bluetooth-enabled electric motorcycles," and the terms state it is "not affiliated with any vehicle manufacturer." That helps it pass Apple review and avoids trademark disputes, but owners searching the store for the brand name won't find it.

### Why now

**The official app has had bad reviews for a long time.** The official Dat Bike iOS app launched in 2021, and in Vietnam it had only 198 ratings, averaging 2.99. In May of 2026, the 4.2.0 version began requiring online verification, and almost every negative review since has said the same thing: it disconnects and won't reconnect, can't connect after a firmware update, and is unusable without internet when you're out (Vietnam App Store reviews, May to 11-03). One one-star review from October 1 reads: "I told the manufacturer and they said to wait indefinitely. There's no other app to use, and they won't fix this. Annoying."

**Android already had a workaround.** In 2026 May 7, an owner named Trương Chương Dương posted DuBike in a Dat Bike owners' Facebook group, a third-party Android app for Dat Bike, showing 1,000+ downloads on Google Play. Since then the group has kept running threads like "official app or DuBike?" and "will a third-party app void my warranty?" The July 1 thread has 43 comments and the November 4 thread has 37. Using a third-party app is already routine for this group.

**iOS was empty.** DuBike never shipped on iOS, so iPhone owners were stuck with the official app. ThatBike fills that gap.

**It supports firmware the official app blocked.** The DuBike author said in the group that from firmware 1.12.1 onward the official side "put a lot of effort into blocking third-party apps." ThatBike has supported 1.12.1 and later from the start, and an owner confirmed in the comments that it works on the Quantum S2 with firmware 1.14.1. So iPhone owners who have upgraded firmware are exactly its users.

### Where users come from: a few owner groups is enough

There's only one channel that can be found: the Dat Bike owners' Facebook group. The author posted "Thatbike release 1.2" there, saying it "reached #18 in the Navigation chart 2 days after launch." The 30 1.3 version shipped in October, and that day it gained 12 ratings (against only 2 before), matching the timing of the post and release.

There's no trace of it on X, TikTok, media, or ads. The comments also sound like the owner community: "Ap ngon cho anh em" (a good app for the brothers), and someone casually asked for a feature: "Would be even better with a regen toggle" and "Hope you keep going and add more useful features."

The growth curve looks like a community being fully covered:

| Date | Cumulative ratings | Vietnam Navigation free chart |
|---|---|---|
| 10-28 | 1 | #21 |
| 10-30 | 14 | — |
| 11-01 | 19 | #55 |
| 11-04 | 25 | #96 |
| 11-06 | 27 | #114 |

(App Store Vietnam, daily data)

After the 10-30 wave, it gained only 1 to 4 ratings a day. Over the same period the official app gained only 6 ratings, suggesting most owners willing to try something new had already tried it.

### Where the money comes from

Essentially none. The website shows a Vietcombank transfer QR code with the text "Buy the author a coffee, completely optional, unlocks no features." The app also has one in-app purchase: "Gold Theme Signature," a gold-and-black color theme, priced at 149,000 Vietnamese dong (about $5.7, App Store Vietnam page, 11-06).

It peaked at #3 (11-03) on the Vietnam Navigation Top Grossing chart, and 11-06 was #15. That ranking shows someone did buy the theme, but the Vietnamese navigation grossing chart is thin, so a few sales can get you on it (inference). Based on the rating count, buyers are unlikely to exceed a few hundred.

The ceiling is visible too. Dat Bike's revenue was 168B Vietnamese dong in 2024 (dantri 2026-02), and the official Android app has 41k installs in total (Google Play, 11-06). Owners are estimated in the tens of thousands. ThatBike is iOS-only, so it can reach only the iPhone slice of that.

### Who it's competing with

| Product | Platform | Scale | Compared with ThatBike |
|---|---|---|---|
| Dat Bike official app | iOS + Android | iOS Vietnam 198 ratings, average 2.99; Android 41k installs | Backed by warranty and able to upgrade firmware, but requires online access and often drops connection |
| DuBike - Dat Bike ++ | Android only | 1,000+ downloads, still updating as of October | More aggressive features: auto-unlock on approach, delivery rider mode, lifting rate and speed limits. ThatBike doesn't touch features that void warranty |
| ViewCHN | Unknown | Not verified | Mentioned only in one warranty discussion thread |

The real rival is the official app. There's another risk from the manufacturer too: it has already blocked third-party apps once with firmware 1.12.1, and it can also pressure owners with "third-party apps void warranty."

### If it were you

**C: learnable, but don't copy it directly.** This single brand's pool is only tens of thousands of owners, its users are already largely covered, and it already holds iOS. What's worth taking is the method: find a smart hardware product with a terrible official app and an active owner community, build an offline, stable alternative client, and cold-start it in owner groups.

**Who it suits** : indie developers who can do iOS or Android Bluetooth work and reverse-engineer BLE protocols, ideally owners or users of the brand themselves, who can speak credibly in owner groups. The goal is a portfolio piece, reputation, and a small group of loyal users, not a living.

**Who it doesn't suit** : anyone who wants to make money from it. Tips plus a $5.7 theme won't support income with a few hundred users. Also not for anyone without the hardware who can't test daily.

**How to do it:**

- Picking the brand: the official app averages under 3 stars in the store, with negative reviews concentrated on connection, login, and mandatory online access; owners have an active Facebook or Zalo group; installs are in the tens of thousands or more. Electric two-wheelers, e-bikes, energy-storage batteries, and smart locks are all worth a look. Vietnam's electric two-wheeler sales were about 209k units in the first half of 2025, up 99% year on year (dat.bike citing Motorcycles Data). There are many brands here, and their apps are generally rough.

- First check whether anyone is already building on both platforms. If someone only shipped Android, as DuBike did, go fill the iOS gap, and vice versa.

- Read-only data, and only controls the official app already offers. Don't touch speed limits or firmware flashing. Leave the brand name out of the app name and state clearly "independent, unofficial."

- Include a simulation mode, so people who haven't decided whether to install can try the interface first.

**How to get users** : no paid acquisition needed. Post version updates, screenshots, and cell voltage comparisons in owner groups, and answer "will this void my warranty?" The first few dozen five-star reviews will mostly come from the group.

**When to move** : there's no clear window. What's worth rushing for are the few weeks after a new model or new firmware comes out, or right after the official app gets criticized, when owners are most willing to switch.

**What would mean you read it wrong** : (1) if someone applies the same method to a much larger brand and reaches thousands of ratings, the ceiling is set by brand size, not the method, and this path becomes more worth pursuing than C; (2) if ThatBike's ratings speed up again after November and the theme purchase breaks into the Vietnam overall chart, owners will pay for a good alternative app, and the paid-model question needs reassessing; (3) conversely, if Dat Bike's next firmware blocks it and owners return to the official app, it shows these apps depend on the manufacturer, and even "learnable" has to be discounted.

In one line: **weak software from a hardware maker is itself an opening.** Opportunities like this rarely appear near the top of the charts; you find them in owner groups.

---

Data and sources: App Store Vietnam daily ratings and charts (10-28 to 11-06); iTunes lookup API and App Store pages (version, release notes, in-app purchases, 11-06); App Store Vietnam reviews (ThatBike and the Dat Bike official app); the ThatBike website and support page thatbike.1001word.com; Google Play (Dat Bike official app, DuBike, 11-06); public posts in the Dat Bike owners' Facebook group (2026-05-07, 07-01, 10-08, 11-04, and the ThatBike 1.2 release post; the body requires login, so only titles and summaries were visible); dantri.com.vn (2026-02), dat.bike. Places marked "inference" or "estimate" are inferred or estimated.

[iOS store page ↗](https://apps.apple.com/app/id6823236685)

**Research notes: competitor table, acquisition evidence, full research report**

Competitors

| Name | Where | Launched | Scale | How it differs from this one |
|---|---|---|---|---|
| Dat Bike official app | iOS | 2021-11(Play 2022-10) | iOS vn 198 ratings, avg 2.99; Play 41k installs, 7 days +1,356 | The official app has warranty backing but requires online verification and often drops connection; ThatBike is offline, connects reliably, and has deeper battery data |
| DuBike - Dat Bike ++ | Android | 2026-05-07 | 1K+ downloads on Play | A first mover in the same niche, Android only, more aggressive features (auto-unlock, lifting limits); ThatBike fills the iOS gap and stays clear of the warranty line |
| ViewCHN | Other | Unknown | Not verified | Another third-party telemetry app, mentioned only in a warranty discussion thread |
| Official apps from brands like VinFast / Yadea | Big-company features | — | — | They only cover their own vehicles, with no overlap with Dat Bike owners |

Where users come from

- **Verified** **Post in the Dat Bike owners' Facebook group** : the author posted "Thatbike release 1.2": "reached #18 in the Navigation chart 2 days after launch" (group 1268399407890468); +12 ratings in one day on 10-30, matching the release timing

- **Verified** **DuBike built community awareness first** : since May the group has had recurring threads on "official app or DuBike" and "will a third-party app void warranty?" (43 and 37 comments)

- Inference **Store search** : the name and description deliberately omit Dat Bike, so it's hard to find by searching the brand; a #21 free spot on the Navigation chart brings a little exposure

- Inference **Ads / TikTok / X / media** : no traces found

## ThatBike - Đồng Hành Xe Điện (iOS 6823236685) research report

Research date: 2026-11-06. Regions checked: the appstore library scanned all regions; it appeared only in Vietnam (vn), with no records elsewhere.

### One line

This is an unofficial iOS Bluetooth client for owners of Vietnam's Dat Bike electric motorcycles (Quantum / ERA series), built by one person. On iPhone it shows the dashboard and per-cell voltages, and can lock, unlock, shut off, and honk to locate the bike. It works offline and requires no account. It took off because three things coincided: **the official app has a bad reputation (Bluetooth drops, mandatory online access)** , **the Android third-party app DuBike had already built a "third-party app" habit among owners** , and nobody had built for iOS. The author only posted in the Dat Bike owners' Facebook group and got a small circle of core owners willing to give five stars. The scale is tiny: 28 ratings in 12 days, and already slowing.

### 1. Data (appstore library, vn region)

- Released 2026-10-25, category Navigation, free, no in-app purchases, requires iOS 17+ (iTunes lookup).

- Rating count: 10-28 was 1,10-30, then 14 (+12 that day), then +1~4,11-06 a day after that, up to 27. iTunes lookup showed 28 ratings that day, averaging 4.93.

- Vietnam Navigation free chart: 10-28 #21 → 11-01 #55 → 11-04 #96 → 11-06 #114, falling steadily.

- Vietnam Navigation Top Grossing chart: 10-31 #10,11-03, peaking at #3,11-06, then #15. **This ranking doesn't reflect revenue** : the app has no in-app purchases, the Vietnamese navigation grossing chart is thin, and free apps also land on it (the same chart includes free utilities like "QH Đồng Nai"), so the "broke into Top Grossing" signal in the recall scoring shouldn't be taken at face value.

- Fast version iteration: 1.1 (10-26) → 1.2 → 1.3 (10-30) → 1.4 (11-02) → 1.4.1 → 1.5.0 (11-04). 1.5.0 added an Apple Watch app, Siri shortcuts ("Khoá ThatBike"), and charge-to-target reminders, and began supporting older firmware below 1.12.1 (release notes).

- Versus the official app: the Dat Bike official iOS app (id1592422856,2021-11, launched 198) has only 2.99 ratings in Vietnam, averaging 10-28. From 11-06 to 6 it gained only 26, while ThatBike gained 41 over the same period. On Android the official app has 7k installs, +1,356 in 11-06 days (googleplay library).

### 2. Competitors

| Name | Where | Launched | Scale | How it differs from ThatBike |
|---|---|---|---|---|
| Dat Bike official app | iOS + Android | iOS 2021-11,Play 2022-10 | iOS vn 198 ratings, avg 2.99; Play 41k installs | Official, backed by warranty and firmware updates. But since 4.2.0 2026-05 requires online verification, and most negative reviews in the past half year are about Bluetooth dropping and failing to reconnect (App Store vn review RSS) |
| DuBike - Dat Bike ++(Trương Chương Dương) | Android(Play) | 2026-05-07 posted publicly on FB groups | Play 1K+ downloads, 10-30 still updating | **The Android pioneer for the same thing** , with more aggressive features: auto-detect unlock, a mode for delivery riders, and removing the discharge current and speed limit. It's not findable on iOS. ThatBike fills the iOS gap |
| ViewCHN | Unknown (mentioned in a Facebook post) | Unknown | Not verified | Another third-party reading app, only named in 2026-07's warranty discussion thread |
| Other brands' official apps (VinFast, Yadea, etc.) | iOS / Android | — | — | They only cover their own vehicles and don't overlap with Dat Bike owners. No third-party iOS client for these brands has been found so far |

Bottom line: competition in this niche is thin. The real rival is the official app, and the only direct equivalent is DuBike on Android.

### 3. Where users came from (growth tactics)

- **Dat Bike owners' Facebook groups: confirmed, and the only channel found.** In groups like "Hội Dat Biker", "Độ xe Dat.bike" and "Dat.Bike Quantum, ERA Hà Nội", the DuBike author has been posting since May, teaching people how to use third-party apps. A thread on "will a third-party app void the warranty" has 43 comments (2026-07-01). The ThatBike author also posted "Thatbike release 1.2" in the group: "Live for 2 days, ranked #18 in the store's Navigation chart" (facebook.com/groups/1268399407890468/posts/2238884204175312; the body needs login to read, so the title and summary come from Jina search results). 10-30's +12 ratings in a single day line up with these posts and releases.

- **Not found:** X (0 mentions in x-radar's 30 days), TikTok (searching "thatbike" returns nothing relevant), press coverage, ads, and Product Hunt show no trace. Store search probably contributes little, because the app name and description deliberately avoid "Dat Bike" (the terms state it is "not affiliated with any vehicle maker"), so owners are unlikely to find it by searching "dat bike".

- The reviews have a clear owner-community tone ("Ap ngon cho anh em" = a good app for the brothers, plus feature requests). They look like organic praise from the group, with no sign of review farming.

### 4. Why it charted

1. **The official app's pain points are public, ongoing and severe.** The official iOS app averages 2.99. Since 2026-05, negative reviews cluster around three issues: "every disconnect means I can't reconnect, I have to delete and re-pair the device", "needs internet to connect outside", and "won't connect after a firmware update" (App Store VN reviews, 2026-05 to 11-03). Almost every ThatBike review compares it to the official app: "doesn't drop like the official app", "better than the official app", "works offline".

2. **DuBike has already educated the market for it.** Since May, the owner groups have been debating "official app or DuBike" (11-04 more threads, 37 comments). Using a third-party app to read battery cells and automate is already normal practice in this crowd. iOS users just never had an option.

3. **It happens to support the new firmware the official app has "locked down".** The DuBike author wrote in July: "Since FW 1.12.1 the official team has put a lot of effort into blocking third-party apps." ThatBike has supported only 1.12.1 and above from the start (per the support page FAQ), and reviews mention it working on a Quantum S2 with FW 1.14.1. So iPhone users who upgraded to the new firmware are exactly its target users.

4. **Detailed execution.** It has a simulation mode (you can see the UI without a vehicle), a lock-screen widget, pairing keys stored in the Keychain, and blocks accidental lock while the vehicle is running. It shipped 5 versions in 10 days and added Apple Watch and Siri. It also deliberately stays clear of warranty red lines: no "remove speed limit" type feature, and "the BMS deep-dive tab only shows what the vehicle reports" (official site).

5. **The base is a group of owners who can afford it.** Dat Bike's revenue was 2024 billion VND in 16.9, is projected at 2025 to 85 billion VND in 130, and it closed a $22.3M Series B+ (dantri 2026-02, cafef 2025-09). Vietnam's electric two-wheeler sales were about 2025k units in the first half of 209, up 99% year on year (dat.bike citing Motorcycles Data; the recall card wrongly labels it "first half of 2026"). But the total number of Dat Bike owners is probably only in the tens of thousands (official Android app 41k installs), and that is its ceiling.

### 5. Differentiation

- Compared with the official app: offline use, no account, no data collection, stable connection, plus deep battery data like cell voltage, voltage spread and charge cycle count, and widgets, Apple Watch and Siri. **This is exactly why it took off** , and almost every review says so.

- Compared with DuBike: **iOS only** (DuBike is Android only), and more restrained. It offers no speed-limit removal or regen tuning, features that could void the warranty (one reviewer asks for "on/off regen", which the author hasn't built). The empty platform plus the safer positioning is why it can take off after DuBike.

### 6. How many people have seen it

**Few people know about it yet.** It only circulates in Dat Bike owner Facebook groups. Nothing on X, TikTok or the press, and no public revenue. Money comes only from voluntary tips via a Vietcombank transfer QR code on the website, which unlocks no features.

### 7. Copycats

No iOS copycat found yet. DuBike was its predecessor (on Android), not a copycat.

### 8. Takeaways

- **"The official app from a hardware maker is bad" is a replicable angle.** Find a smart hardware product (e-bike, electric scooter, battery, smart lock) with a large installed base, an official app averaging below 3, and an active owner community. Reverse-engineer the BLE protocol to build an offline, stable client, and cold-start it in owner groups without spending a cent on promotion.

- **Claim each platform separately** : if someone has only done Android, go build the iOS version, and vice versa.

- **Compliance wording** : leave the brand name out of the app name and description, state clearly that it is "independent, unofficial". That helps it pass review and lowers trademark risk.

- **Be clear about the limits** : the ceiling is this brand's owner count (tens of thousands); the maker can cut it off at any time with a firmware update (Dat Bike has already blocked it once, 1.12.1); and the maker can use "third-party apps void the warranty" as leverage. For now, monetization is tips only.

### 9. Still unclear

- The full Facebook post and its engagement numbers (login required); which other groups the author has posted in.

- How many active users it really has, and how much tip revenue comes in.

- Whether Dat Bike will block ThatBike too in its next firmware update.

- What ViewCHN is, and how big it is.

- The recall card's claim that "DuBike has started to follow" is inaccurate: DuBike came out more than 5 months before ThatBike, and it's on Android.

### Sources

- appstore library: app_day, chart_rank (app_id 6823236685, 1592422856, vn, 2026-10-28 to 11-06); googleplay library: app_profile (com.dat.bike, 11-06)

- iTunes lookup / reviews RSS(vn): ids 6823236685, 1592422856, 6826650160 (Hanko sudoku, newly launched by the same developer 11-02)

- Official site [thatbike.1001word.com/](https://thatbike.1001word.com/), /support, /terms

- DuBike Play page [play.google.com/store/apps/details?id=com.du.dtc.bike](https://play.google.com/store/apps/details?id=com.du.dtc.bike)

- FB: DuBike release post facebook.com/groups/1107312953766926/posts/1750928289405386 (2026-05-07); warranty discussion thread facebook.com/groups/6732749560178166/posts/27310356368657517 (2026-07-01); DuBike connection tutorial facebook.com/groups/147328209185093/posts/2206468169937743 (2026-10-08); "Datbike or Dubike" thread facebook.com/groups/6732749560178166/posts/28897799799913158 (2026-11-04); ThatBike 1.2 release post facebook.com/groups/1268399407890468/posts/2238884204175312

- Dat Bike official app 4.2.0 announcement facebook.com/datbikevn/posts/…/1016888757527288 (2026-05-09)

- dantri.com.vn (2026-02-17), cafef.vn (2025-09-18), dat.bike/xe-may-dien

This article was written by AI from public data and the data we collect daily. Numbers are sourced, and inferences are labeled.