Pay, and your phone pops up to log it: a bookkeeping app built by a Hong Konger using iOS 27's new toggle

A Hong Kong bookkeeping app called "Ching", built by one person, hit the iPhone in Oct 13. In Oct 18 they posted a 9-second demo video on Threads, which has been seen 420k times. It has no unique technology. It got three things right: it entered right when iOS 27 opened a new switch; it adapted a dozen-plus local Hong Kong payment notification formats one by one; and it explained everything in a video anyone can understand. Below: how it took off, where the money comes from, who the competitors are, and whether copying it in another city is worth it.

A 9-second video

In Oct 18, the Threads account @chikching.app (bio: "C兄|香港記帳app") posted a vertical video with this caption:

This is how an expense tracker app should work: once you've paid, you don't need to log it in the app. Just tap the notification to record it.

The video has three steps: phone payment → a Ching notification pops up at the top of the screen, with amount, merchant and category already filled in → tap "confirm", done. The download link is in the creator's own first comment, a tracked link with a channel tag.

The video has now had 422k views, 4.5K likes, 275 replies and 5.6K shares. For a city of only a few million people, with far fewer Threads users, that is big-account-level exposure.

The numbers show the result clearly. In Oct 20, a competitor's comparison article on Hong Kong bookkeeping apps listed Ching at only 8 ratings on the Hong Kong App Store. By Oct 28 it was 50, by Nov 6 87, and in the last 7 days it has been climbing by 1–6 ratings a day. On Google Play, installs went from 10/20 to 436, and four days later reached 1,189 (third-party estimate), after being only single digits per day before. On the Hong Kong App Store finance Top Grossing chart, it has ranged from #10-28 up to #65,10-29, #20,11-03, and at its best #13,11-06 and #17.

What it actually does

Ching is made by I Love Working Limited, a company with just this one app. The founder wrote on Threads that the app "had to be built by me." The official site tells the story: "At first, my big sister kept our household numbers in a Google Sheet." He wanted to build a shared expense-tracking app for the two of them, and while building it he wondered: phones already get payment notifications, so why type every transaction by hand? Six months later, Ching existed. The name imitates the "chik-ching" sound of coins, and it is also the Cantonese word for "senior schoolmate."

Its approach runs against most finance apps. It does not connect to banks or ask for passwords, and only reads payment notifications on the phone. When Octopus charges HK$11.0, a notification arrives, Ching recognizes "Kowloon Motor Bus / Long Win, Transport", and pops up for you to confirm. The official site lists some twenty notification sources: Octopus, PayMe, AlipayHK, HSBC, BOCHK, Hang Seng, Standard Chartered, Mox, ZA Bank, Futu and more. About half are marked "limited support". For payments whose notifications can't be read, you can also photograph a receipt or paper slip and it will be recognized.

The Android version launched in June, since reading notifications has always worked on Android. The problem was the iPhone. Previously, iOS Shortcuts could only access transactions from Apple Wallet itself; push notifications from PayMe or bank apps were out of reach. iOS 27 added "trigger when a notification from a given app arrives" to Shortcuts. With that door open, Ching brought over the setup that already worked on Android, launched on iOS in 10-13, and the App Store listing states "requires iOS 27".

Why Hong Kong users are buying in

Hong Kong is an underserved market for bookkeeping apps. Taiwan has e-invoice carriers, mainland China has Alipay and WeChat bills, and Hong Kong has neither. The long-established Planto connects to banks and asks for login credentials, and some Threads users complain it is "sometimes delayed, sometimes breaks". Bookkeeping apps from Taiwan and mainland China don't recognize Octopus or PayMe, and some Hong Kong users say outright "mainland and Taiwan apps don't work here".

So reviews include comments like this (App Store Hong Kong, 10-20):

Waited years for an app like this at last

Another (11-01): "When paying with Apple Pay, it pops up within seconds to remind me to log it." 7 reviews are all 5 stars, and two specifically praise customer service for being patient. The two requests users raise: CSV import, and skipping even the "confirm" tap.

The most common skeptical reply under the viral post is "the new iOS Shortcuts can already do this". The developer's answer is that Ching's value is integrating shortcuts and bookkeeping and setting it up for you. That is half right: on an iPhone the setup still takes several steps (get the shortcut, add notification triggering in the Shortcuts app, turn off "Notify When Run", choose "Always Allow"). The official FAQ has a long section walking through this, plus a "shortcut diagnostics" button. For an ordinary user, though, having someone write the tutorial and tune the notification format for each bank is already "no DIY needed".

Where the money comes from

The free version offers unlimited manual entry and Android notification-based logging. The paid "醒目的Ching" costs HK$28/month or HK$238/year. It adds 300 image recognitions per month (3 free), unlimited AI spending analysis, cloud backup, and unlimited budgets.

Revenue is not public. Ranking in the 13–20 range on the Hong Kong finance Top Grossing chart shows people are clearly paying. But that chart's bar isn't high, and converting it to money, the inferred range is a few thousand US dollars a month (an estimate, low confidence). We found no evidence it runs paid ads; growth has come mostly from that video and organic reposts.

Who it's competing with

A developer wrote on 11-01: "So many auto-bookkeeping apps on iOS lately." After 27, this category popped up in Hong Kong and Taiwan at the same time. Technically anyone can build it. Ching is ahead on two things: the most complete local payment-source integrations, and that one video.

If it were you

B: Worth a try, but it's a small market and the window is closing. iOS 27's notification triggers open a new door. "Read payment notifications, tap to log" works in any city with local wallets. But Hong Kong already has three or four players in this space, Taiwan has people building too, and the ceiling for paying users in a single city is low.

Who it's for: a solo dev or a two-person team who lives in a market with lots of fragmented payment notifications (PayNow and GrabPay in Singapore, Touch 'n Go in Malaysia, MPay in Macau, LINE Pay and JKOPay in Taiwan), has at least a dozen local bank and wallet apps on hand, and is willing to collect the push notification texts one by one and adapt the formats. It's grunt work, and it's the only real moat.

Who it's not for: anyone targeting mainland China (Alipay and WeChat already have bills, so users aren't short on tracking); anyone counting on a technical lead (the mechanism is open to anyone, and the iPhone setup steps can't be shortened further); anyone aiming at the US or UK (bank connections and Plaid are mature there, and notification-based logging isn't a must-have).

How to build it: launch on Android first. Android already grants notification-reading permission, so you can get the format adapters working and build your first user base. For the iOS version, make it "one install shortcut + one illustrated setup guide + one diagnostic button," and like Ching, put privacy front and center: no bank connections, data stays on device. The free tier has unlimited logging, and paid features are image recognition, cloud backup and AI analysis, priced at about one to two local coffees.

How to get users: copy Ching's 9-second video: real footage of a payment, the notification popping up, tapping confirm, with one line of local slang, posted where locals are most active (Threads in Hong Kong; TikTok and Threads in Malaysia and Singapore, inferred). Put the download link in the first comment and use tracking links per channel. Once the video takes off, immediately post a clear privacy explainer and reply to comments one by one.

When to get in: the next few months, while iOS 27 users are still upgrading in waves and competitors haven't clustered in your city yet. Ideally launch before January 2027 to catch the New Year budgeting wave, when people start tracking spending.

What would mean you misread it: ① Ching's Hong Kong personal finance chart position falls out of the top 50 in December, which would mean the users from one viral video didn't stick and didn't pay; ② Apple adds a cross-app spending summary to Wallet or its built-in journaling app; ③ the main wallets or banks in your market strip the amount and merchant from push notifications. With no notification content, this whole approach has no foundation.

Sources

• App Store Hong Kong rating counts and Finance category charts: daily records from 2026-10-28 to 11-06; reviews from the App Store Hong Kong store (10-20 to 11-01).
• Google Play installs: 2026-07 to 11-06. October figures are AppstoreSpy estimates.
• Threads: @chikching.app, 10-15 and 10-18 posts (views, likes and shares as seen by 11-06).
• Official site chikching.app (founder's own account, notification source list, iPhone setup FAQ, pricing, 11-06).
• receiptiq.me comparison article on Hong Kong bookkeeping apps (2026-10-20).
• iOS 27 notification triggers: macstories.net and related r/shortcuts threads.