Couple tracks spending and raises pets together: a Taiwanese couple's app charted #38 in Top Grossing, but it hasn't really taken off yet
What it is A shared expense-tracking app for Taiwanese couples: two synced ledgers, AA splitting, saving together. Every entry you log turns into food for a pet the two of you raise. VIP subscription.
Why it caught on It hasn't really. The developer couple built a small user base by posting on Threads themselves, with a "cute and you can raise a pet" hook and very fast iteration. Taiwan's finance Top Grossing chart has a very low bar, so a few subscriptions were enough to reach #38.
CHow you could follow it Don't copy the theme, copy the mechanics: "one person plays first, then invites the partner", "rewards require both people", and "logging becomes feeding". These can move to chores, saving, or long-distance relationship scenarios, with one practical feature people want to share.
- Data (updated daily) · First released 2026-08-25 · Taiwan rating 75 · 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 dayiOS · Ratings count · Taiwan Data 2026-10-28 → 2026-11-08 (12 days, 12 observations). Apple doesn't publish download counts; rating growth is a proxy for downloads.
A Taiwanese couple (girlfriend runs marketing, boyfriend writes code) built "我們的存摺", stitching together shared expense tracking, AA splitting, and raising a pet together. 11-06 it reached #38 in Taiwan's App Store finance Top Grossing. That rank looks far better than its real scale: the Taiwan finance Top Grossing chart has a very low bar, and a few subscriptions can push you into the top 40. What's worth looking at is its product design, not its ranking.
"The app is well built, but nobody uses it, and it's really heartbreaking"
In 2026 Sep 29, the developer posted from their personal Threads account @diary_zy3: "Coming back to vent a bit: my new app is getting less and less traffic. The app is well made, but without users it's really heartbreaking 🥹" It got 684 views, one of the best-performing posts on that account.
The app had only been live for a month then (Aug 25). Over the next month and a bit, it slid from 57 to 188 on the Taiwan Finance Top Free chart, then suddenly showed up on the Finance Top Grossing chart in Nov 2, where it ranked #38 11-06. Over the same stretch, its rating count in Taiwan went from 59 to 74,10, adding 15 in ratings.
What it is
A shared couple expense app that only does Traditional Chinese and only ranks in Taiwan. The developer has just this one app, published under "LedgerCouple Studio".
- Tracking: a shared ledger for the two of you, synced in real time, with private accounts the partner can't see. Works with iPhone Shortcuts to log a card charge automatically. Also receipt barcode scanning, recurring bill reminders, and monthly budgets.
- Splitting and saving: record who paid first, and the home screen shows who owes whom how much. Trip ledgers and multi-person splits. Shared savings goals (travel, wedding, buying a home).
- Pet raising: every entry you log becomes food, and you hold "big cannon" to feed the pet you raise together. Both of you must log every day to light the "flame", and only then does the pet grow. The store page says: "It won't get sick or die, it will just wait for you at the door."
- Couple features: a daily question (revealed only after both have answered), guess-the-price, a couple map, "talk about this" on any entry, a date-night pocket list, and the pet sends postcards when it goes out.
Pricing is VIP: NT$150 a month, NT$990 a year, or NT$1,980 for a one-time purchase (about $4.7 / $31 / $62). It also sells pet outfits and a "little footprint" virtual currency (Taiwan App Store in-app purchase prices, 11-06).
What #38 on Top Grossing actually means
Not much. 11-06 On that same Taiwan finance Top Grossing chart, #25 has only 1 ratings, #35 has 0, #42 has 8, and the "伴伴帳" at #58 has 58. On this chart, the top 40 roughly need only a trickle of subscriptions each day. Working backward from its prices and this threshold, revenue is probably somewhere between a few hundred and two or three thousand US dollars a month (estimate, no public data).
Other signals also point to "still very small": the official Threads account @coupleledger has 332 followers, and single posts usually get a few dozen to just over a hundred views. There are 0 Instagram posts. No press coverage, no big accounts resharing it, and no paid ads found.
Where users come from
Almost entirely the two founders posting on Threads themselves:
- The couple persona. The official account bio reads: "A bookkeeping program born out of not wanting to fight about saving money. Now run and developed by the couple together." They post couple-life bits ("guess what I ate for lunch, girlfriend-sama") and engagement questions like "What's the cheapest date you've ever been on?" That got 26 replies, and they funneled commenters to the download.
- Piggybacking on a viral thread. 11-03 signed up to self-promote under a viral post "recommend 100% Taiwanese apps" (462 likes, 194 replies). That comment got 77 views.
- Tutorials tied to a platform event. A pinned post teaches people to use the "when a notification is received" automation added in iOS 27, so LINE Pay, JKOPAY, and bank notifications log automatically. This is the shared topic among Taiwanese expense apps on Threads this autumn, but it isn't the one leading it: a similar post from DuoPurse on the same subject got 958 likes and 896 reposts (10-26).
- A few organic recommendations. One user posted, "This accounting app is so cute, you can even raise a pet... works fine for one person too" 10-25, with 192 views. When others recommend it, the reasons are "cute, you can raise a pet." Nobody talks about the bookkeeping itself.
- Inviting the partner from inside the app. One person starts, logs 3 entries, the box at the door opens and the pet comes out; then they send an invite link to their partner. The flame, the daily question, and the pet going out all require both people, so each user naturally brings in one more (inference, no pairing-rate data).
- Adding Android. Around 11-05 it launched on Android, solving the problem of "one of us uses an iPhone and one an Android, so we can't log together." One of the earliest store reviews reads: "Does this only work on iPhones?" (10-27)
Who it's competing with
This is a crowded space, and over the past 2026 years a large batch of similar one- or two-person projects has appeared:
| Product | Scale (Taiwan) | How it differs |
|---|---|---|
| Shareroo shared ledger (Japan) | 8,813 ratings, finance Top Grossing #11–32 | The established multilingual pure-utility app, the one that actually makes money in this space |
| Ban Ban Zhang (Partner Ledger) | iOS 58 ratings; Android 1,799 installs, 7 over 244 days | Launched 11 days earlier, also driven by the developer posting on Threads, no pet-raising. The most direct competitor |
| DuoPurse | Store data not verified | Built around automatic logging from card charges, with far more voice on Threads |
| Expense City | 86,277 ratings | The predecessor of "expense tracking + growth game", aimed at individuals |
| CWMoney, Simple Expense Tracker | 85k–107k ratings | Big expense apps with a built-in "shared ledger" |
| SumOne, Between, PicPet | 22k–44k ratings; PicPet has 300k users after 4 months | Doesn't track expenses, but competes for the same couples' "use it together" time |
There are also Shiguang Accounting, Aijiji, FINXI, DuoDivvy and others, all with under 70 ratings. Someone on Threads put it bluntly: "People joke that there are a lot of expense apps, but the topic of expense tracking still genuinely interests users."
What it got right
- The need is real and lasting. Dcard, PTT, and Threads have posts every year asking "recommend a shared expense app for couples", and many people end up cobbling something together in Google Forms.
- Turning "keep logging" into "feed the pet", and promising the pet will never die, so giving up carries no guilt.
- Locked to two people: every reward needs both people, so they naturally keep each other going (inference, no retention data).
- Fast iteration, replies to reviews: 10-13 to 11-03 shipped 8 versions; 10-26 a batch of one-star reviews saying "suddenly can't log in" and "home screen freezes," and the developer replied by name within two days confirming the fix.
Its differentiation got it noticed, but it hasn't turned into growth yet. The practical feature that actually gets shared in this category is "automatic logging from card charges", and on that point it is a follower.
If it were you
In one line: there's a lot to learn here, but if you build a couple expense app the same way, you'll most likely end up stuck at "no traffic", just like it.
Who it's for: indie devs already building expense or check-in apps, or couple and family products, who want to borrow its "two-person lock-in + growth" design, and people who want to test willingness to pay cheaply in a small market.
Who it's not for: anyone planning yet another couple expense app in Taiwan. Established tools, the shared features of big expense apps, and a batch of same-period launches already fill the space, and the channel (Threads) is held by competitors who are better at content.
How to do it: copy the mechanics, not the theme. "One person starts, then invites the partner", "every reward requires both people", and "the tool action becomes the feeding action" can all move to other two-person use cases (splitting chores, saving together, check-ins for long-distance couples). If you want a different market, look at whether Japan, Korea, Hong Kong, or English-language markets have "shared couple expenses" products with a growth mechanic, though Shareroo and Between are established there too.
How to get users: learn its Threads playbook: founder persona, couple-life bits, engagement questions, and tutorials tied to new platform features. But to reach DuoPurse's level, you need a practical feature people want to share. "Cute" alone isn't enough.
When is "before": the iOS 27 notification auto-logging wave is from this autumn. To get in, you need to move before it becomes standard in every expense app, which probably means the next few months.
What would show you're wrong: if within a month or two after its Android launch its ratings and installs clearly speed up (say, Taiwan iOS ratings pass 300 in a month and Android adds thousands a week), that would show the "couple + pet" path can gain traction on its own, and the idea deserves a second look.
Research notes: competitor table, acquisition evidence, full research report
- Competitors
Name Where Launched Scale How it differs from this one Shared ledger Shareroo iOS 2019-09 tw 8,813 ratings, Finance Top Grossing #11–32 Long-running multi-language pure utility (split bills, advances, AI receipts), no pets or couple gameplay Ban Ban Zhang (Partner Ledger) iOS 2026-08-14 tw 58 ratings, Finance Top Grossing #58; Android 1,799 installs, 7 days +244 Launched at the same scale, also relies on the dev posting on Threads, also has shortcut auto-bookkeeping and calendar, but no pet-raising gamification DuoPurse iOS 2026 Not captured in our database; one Threads auto-bookkeeping post 958 likes, 896 shares Mainly iOS 27 notification-based auto-bookkeeping (credit cards, LINE Pay, JKOPay); far more buzz on Threads than Bankbook; no pets ienon iOS 2023-12 tw 501 ratings, Finance Top Free #19–54 Family / couple shared calendar + bookkeeping + to-dos, leaning toward family management Manebo iOS 2021-09 tw 219 ratings Completely free, no-signup shared bookkeeping tool for couples Expense City iOS 2017-02 tw 86,277 ratings, Finance Top Grossing #26 Predecessor with bookkeeping + raising game, but aimed at individuals, not couples NYAKEI Cat Can Ledger iOS 2026-07-01 tw 19 ratings, Finance Top Grossing #49–194 Cute cats + personal bookkeeping Moneko AI bookkeeping assistant iOS Unverified Unverified AI chat bookkeeping + shared couple budget, targeting the English market Shared ledgers in CWMoney / Simple Bookkeeping / Money+ Big-company features 2015–2020 tw 8.5K–10.7K ratings A shared feature inside a large bookkeeping app, not a couples product SumOne / Between / PicPet iOS 2011–2025 SumOne tw 22,022 ratings; Between tw 43,629; PicPet 4 months, 300K users Couple social / raising pets together, but no bookkeeping; competes for the same couples - Where users come from
- Verified Official Threads account + developers' personal posts: @coupleledger bio reads 'co-run and developed by the couple'; posts couple jokes and questions ('the cheapest date', 26 replies) that lead to downloads; portaly.cc/couple
- Verified Self-promotion in a trending thread: 11-03 self-promoted under @pink.chou1113's '100% of Taiwan apps recommended' thread (462 likes, 194 replies), 77 views on the comment
- Verified iOS 27 notification auto-bookkeeping tutorial: the pinned post shows how to auto-log LINE Pay, JKOPay and bank notifications; similar apps DuoPurse and chikching also target this topic
- Verified A few users recommending organically: @flower.0113 10-25 posted a recommendation (192 views)
- Inferred In-app couple invite: one person logs 3 entries, then sends an invite link to their partner; rewards like flame streaks require both to record
- Verified Android launch: around 11-05, the official account announced the 'Android version is officially live' (app.coupleledger), solving the one-iPhone-one-Android couple problem
- Inferred Paid ads / influencers / media: none found
Our Bankbook – Couple Bookkeeping with Pets (iOS 6800684358) Research Report
Research date 2026-11-06. Data from our appstore / googleplay databases (10-28 to 11-06), App Store pages, and public Threads pages (read via Jina).
In one sentence
A couples' shared bookkeeping app from Taiwan, made by a couple (the girlfriend writes posts, the boyfriend codes, credited as 'LedgerCouple Studio'; the developer chuang chia chang has only this app): ledgers sync in real time, AA splitting, joint saving; every entry becomes feed for a pet the two raise together, fed with 'cannons'. 2026-08-25 launched, Traditional Chinese only, ranked only in Taiwan; 11-05 shortly before, just released an Android version (package app.coupleledger).
Verdict: how well is it actually doing
It hasn't really taken off. It's a small product amplified by the low bar of Taiwan's finance Top Grossing chart.
- Ratings: 10-28 at 59,11-06 at 74,10 days +15 (about 1.5 per day; appstore database, tw).
- Ranking: 10-28 to 11-01 on Taiwan's finance Top Free chart, sliding from #57 to #188; from 11-02 it appeared on finance Top Grossing at #38–99, peaking at #11-06 on 38 (appstore database, app_day).
- The bar for the Taiwan Finance Top Grossing chart is very low: 11-06 On the same chart, #25 Bujji has only 1 ratings, #35 ETH Mining has 0, #42 Daak has 2 with 8, #54 貓缶簿 has 19, and #58 伴伴帳 has 58 (appstore table v_chart, tw / genre 6015 / grossing / 2026-11-06). So #38 mostly means a handful of subscriptions a day, not real revenue at scale.
- The developer wrote on their personal account @diary_zy3 in Sep 28 (Threads): "New apps get less and less traffic these days. The app is good but with no users I'm really going to cry." This is first-hand evidence that growth had stalled by late September.
- The official Threads @coupleledger has only 332 followers, and single posts usually get a few dozen to about a hundred views (e.g., 10-14 at 65 views, the self-promo post at 77 views); IG @coupleledger has 0 posts and 0 followers; YouTube @LedgerCouple has one demo short with 0 likes.
So the 'people are already paying' part of the recall score (76) is roughly right, but the scale is tiny. What's worth studying isn't that it 'succeeded', but a low-cost, replicable playbook for indie bookkeeping apps in Taiwan, plus the phenomenon of a low bar on the Top Grossing chart.
Competitors
Taiwan's "couples / shared expense tracking" niche is crowded, and in 2026 a wave of similar indie apps showed up (mostly built by one or two people, quite possibly with AI assistance: this app shipped 8 versions from 10-13 to 11-03, including 2.4.1, 2.4.2, 2.4.4, 2.4.5, 2.4.6, 3.0.0, 3.0.1, and 3.1.0).
| Product | Platform | Launched | Scale (tw) | How it differs |
|---|---|---|---|---|
| Shareroo shared ledger (Japan, takaaki ono) | iOS | 2019-09 | 8,813 ratings, Finance Top Grossing #11–32, 7 days +23 ratings | Long-running, multi-language, pure utility (split bills, advance settlement, AI receipts); no pets or couple gameplay. The one in this niche that actually makes money |
| Companion Ledger (WEI-HSUN LUNG / BrokenOAO) | iOS + Android | 2026-08-14 | iOS 58 ratings; Android 1,799 installs, 7 days +244 | Launched almost simultaneously, same scale, also relying on the Threads developer posting, also with shortcut auto-bookkeeping and calendar; no pet-raising gamification. The most direct rival |
| DuoPurse(@duopurse_app) | iOS (Android coming) | 2026 | Not captured in our database; one Threads post about auto-bookkeeping 958 likes, 896 shares (10-26) | Mainly iOS 27 notification-based auto-bookkeeping (credit cards, LINE Pay, JKOPay), much more buzz on Threads than Bankbook; family / couple sharing |
| ienon(Dear Inc.) | iOS | 2023-12 | 501 ratings, Finance Top Free #19–54 | Family / couple shared calendar + bookkeeping + to-dos, leaning toward family management |
| Manebo (Shibapp, Japan) | iOS | 2021-09 | 219 rating | Completely free, no signup, pure utility |
| NYAKEI Cat Can Ledger (MOCHIU) | iOS | 2026-07-01 | 19 ratings, Finance Top Grossing #49–194 | Also a "cute animals + expense tracking" app, but for personal finance |
| City Ledger (SPARKFUL) | iOS | 2017-02 | Rated 86,277, #26 in the Finance bestseller chart | The predecessor of "expense tracking + farming game" (building a city with your spending), aimed at individuals |
| Moneko AI bookkeeping assistant | iOS + Android | Around 2025 | Unverified | AI chat expense tracking + shared couple budget. Also uses iOS 27 notifications to auto-log expenses, with an English market |
| Other similar apps launched in the past 2026 years | iOS | 2026 | All rated < 70 | CairnBook (shared expense tracking), 愛計家 (family expense tracking), FINXI (shared ledger, #47 in Finance bestsellers), Daak 2, Bujji and others |
| Shared features from big players and veteran expense apps | iOS / Android | Early on | CWMoney rated 85,300, Simple Expense Tracker rated 106,590 | CWMoney, Money+ and Simple Expense Tracker all have a "shared ledger" feature, but they are not couple-focused products |
| Non-expense couple apps | iOS | — | SumOne rated 22,022, Between rated 43,629, PicPet (Taiwan, 4 months, 30 10K users) | They compete for the same couples' "use it together" time. PicPet shows that "raising a pet together as a couple" can go viral on Threads in Taiwan |
There is no such thing as "no competitors": there are many similar apps, and DuoPurse in particular has clearly more reach than this one on the same channel (Threads).
Growth tactics (evidence)
- Organic Threads content + developer persona (confirmed). The official account @coupleledger's bio reads "A ledger app not born from fights over saving money. Now co-run and co-developed by the couple", and the developer's personal account @diary_zy3 has 49 followers. The content is couple daily jokes ("Guess what I had for lunch, girlfriend-sama"), engagement questions ("What's the most budget-friendly date you've ever had?", 26 replies), with download links dropped in the comments. The link-in-bio is portaly.cc/couple.
- Piggybacking on a trending thread (confirmed). 11-03 self-nominated under @pink.chou1113's "recommend 100% Taiwan apps" thread (462 likes, 194 replies), and that reply got 77 views; also left setup tips under other people's posts about budgeting apps.
- Tutorial content on auto-logging via iOS 27 notifications (confirmed). A pinned post explains how the "When receiving a notification" automation in iOS 27 can auto-log LINE Pay, JKOPay and bank notifications. This was a shared topic for Taiwan expense apps in 2026 autumn (DuoPurse and Hong Kong's chikching both played this card, and one chikching post got 4.5K likes). 存摺 rode this wave rather than leading it.
- Small amount of organic / word-of-mouth recommendations from users (confirmed, very small volume). @flower.0113 posted on 10-25: "This ledger is really cute, it even lets you raise a pet... usable even if you're alone" (192 views), and created the tag "我們的存摺" (Our 存摺).
- In-app couple invitation (inferred). The design has one person log 3 entries to unlock the unboxing, then send an invite link to their partner. Each user naturally brings in another person. Flame streaks, daily questions and pet travel postcards all trigger only when both partners log expenses.
- App Store search (inferred). The name stacks "couple expense tracking" and "raising pets", with the subtitle "Couples and spouses track expenses together · AA splitting · Save money together". It shows up alongside 伴伴帳 in the App Store "You might also like" section.
- Android launch (confirmed, around 11-05). The official account announced "The Android version is officially live", solving the problem of couples where one uses an iPhone and the other an Android not being able to use it together. The 11-06 rating increase +6 may be related to this (unverified).
- Not found: paid ads, creator partnerships, media coverage, Dcard/PTT discussions, mentions on X. No TrustMRR listing or founder revenue posts either.
Why it achieved this level
- The need is real and long-standing: on Dcard, PTT and Threads, posts asking for "couple/spouse shared expense apps" appear every year, and many people end up making do with Google Forms (like that @excel.captain post).
- Couple products carry built-in virality with 1 bringing 1, and because the two partners keep each other accountable for logging, retention is likely better than for solo tracking (inferred; no retention data).
- It tackles the difficulty of sticking with expense tracking through gamification: pets, flame day streaks, room decorations, a paw-print shop. It follows the same logic as City Ledger and PicPet, but applied to couples.
- Very fast iteration and responsive to reviews: since October it has shipped a new version roughly every 2–3 days, and the developer publicly replies within 2 days to negative reviews (login failures, widget freezing), explaining the fix.
- The bar for the Taiwan Finance bestseller chart is very low. A few VIP subscriptions can put an app in the top 40, so in the data it "looks" like it has taken off.
Differentiation
Its biggest difference from competitors is "couples tracking expenses together + raising pets together + a pile of couple social features" (daily questions, guess-the-price, couple map, whispers, date wishlist, pets sending postcards). Shareroo / Manebo / 伴伴帳 are tools; City Ledger / 貓缶簿 are gamified personal apps; SumOne / Between / PicPet are couple social apps that don't track expenses. It stitches all three together.
This differentiation is why it gets noticed (on Threads, people recommending it talk about "so cute, and you can even raise a pet"), but it has not yet turned into growth: the developer said in September there was no traffic, and in 10 days the rating only rose by 15. What made the similar DuoPurse take off was the practical point of "auto-logging card payments", and on that point 存摺 is a follower.
Visibility
Few people know about it yet. The official Threads account has 332 followers and single posts get dozens of views. No media coverage, no big accounts resharing it, no public revenue.
Copycats
No one is specifically copying it, but a wave of similar apps appeared around the same time: 伴伴帳 (launched 11 days earlier), CairnBook, 愛計家, FINXI, "AA分帳|夫妻情侶共用帳本", DuoDivvy - Couple shared expense app and others. This suggests a trend of "everyone is building an expense app" (on Threads, @stamp.ossan: "People joke that everyone is making expense apps, but users are still genuinely interested in the topic of tracking expenses").
Takeaways
- The invitation mechanic for couple/two-person products: get one person hooked first (log 3 entries to unbox), then use an invite link to bring in the partner, with every reward requiring both people to participate.
- Turn a tedious tool action (expense logging) into a feeding action, and promise "it won't die, it will just wait for you at the door" to reduce the guilt of quitting.
- Small countries and niche category bestseller charts have a very low bar: getting into the top 40 of Taiwan's Finance bestsellers takes only a few subscriptions. If you want chart placement as credibility or to test willingness to pay, the cost is low.
- Making tutorial content around a platform event (iOS 27 "When receiving a notification" automation) is currently the most effective topic for Taiwan expense apps on Threads.
Still uncertain
- VIP pricing and subscriber count (the App Store page did not capture the in-app purchase prices).
- Whether the sudden appearance in the bestseller chart from 11-02, the 11-06 rating increase of +6, came from the 3.0 redesign, the Android launch, or a particular exposure event cannot be separated.
- Whether it runs ads: our ad library only tracks products on the watchlist, so not finding any doesn't mean none were run.
- Retention and couple pairing rate are unknown.
Sources
- appstore database: app_day (app_id 6800684358, 1475406336, 6797804282, 6471992115, 6749444726, tw, 10-28 to 11-06), v_chart (tw Finance bestsellers 2026-11-06), app / app_name name search.
- googleplay database: com.dragons.oao.coupleledger (伴伴帳) app_profile.
- App Store: apps.apple.com/tw/app/id6800684358 (version history, developer replies). iTunes lookup (version 3.1.0, 2026-11-03).
- Threads:www.threads.com/@coupleledger ;www.threads.com/@diary_zy3/post/Dd3GZpvoIur ;www.threads.com/@coupleledger/post/DfT5MKWD_XF ;www.threads.com/@coupleledger/post/DfOu2qXj8uw ;www.threads.com/@flower.0113/post/De8sZnmkkdT ;www.threads.com/@duopurse_app/post/De8M-X4E4qZ ;www.threads.com/@banbanledger ;www.threads.com/@excel.captain/post/DNCSeS4vcuS
- portaly:portaly.cc/couple
- PicPet coverage: meet.bnext.com.tw/articles/view/52977