u/Aware_Web9715

My first beta release of Zoro, a wealth tracking app was met with mixed reactions. People hated the idea of LLM advice but loved the idea of privacy first tracking. The problem is ofcourse data entry and updating it, without an api

Bank APIs make tracking easy but the privacy cost is too high for some, for me it just didn’t work. I have assets in multiple currencies and counties.

Excel files are of course still great, it's been incredibly hard to build something better than a google sheet that lives on my phone but that is the goal for the first version and for me to release in the App Store first and Play Store next (cause I have an iPhone and you need an Android device to publish in the play store)

The app itself is a ledger of your financial life; it's built for simplicity not to track every expense line item. Everything is stored locally on your device. There is no cloud syncing, no bank sharing and no selling your data. If you delete the app, the data is gone.

I have started using LLMs to make it easy to import data. Can upload a password protected PDF, the app allows you to input the password and converts it to a machine readable format. The LLM then parses it to save both structured data and a more descriptive context file.

So to get from here to the App Store release there are three different directions I could go in.

1. Apple Intelligence feature things like “hey siri sent think to Zoro” or using your camera to extract data from documents

2. Way to export data or share it with others to get active feedback. Maybe a human advisor in the loop type of thing

3. Agent builder to customize logic and in app execution of tasks such as updating exchange rates, auditing spending, planning for retirement

Would love to get feedback on what approach makes more sense and / or if there is anything that would make you use a tracking app over a spreadsheet.

Technical details: It’s built using flutter (and several packages for PDF extraction, markdown formatting etc) with a bridge to native functionalities including apple on device intelligence but it can’t do much as the context window is limited and PDF files of bank statements can be large. So can add api keys Gemini seems to work quite well with PDF files even uploading them directly but it’s handled on device to deal with the password. There is intentionally no database the data is stored saved on device is an on device json object linked to markdown files with context. Does that scale for on device storage ? At what point does the json break?

Did a bit of research and some testing and it seems fine if set up well and there is hygiene in how components are hydrated on app load etc.

Working on a personal finance app (Zoro) with a privacy first philosophy. No bank sync, no cloud everything stays on device. I’m currently implementing the Apple Intelligence Foundation Models (via a Swift bridge) for OCR document extraction and I’m at a crossroads with the local database choice.

I’m persisting most of my Flutter app state as one JSON file under the application support directory, named something like app_state.json. The root map includes a formatVersion int, if it doesn’t match what the app expects, I treat the file as invalid and start fresh.

Serialization is hand-written maps to/from my models (no json_serializable for this blob). I use dart:convert for encode/decode and dart:io File for I/O. Saves are atomic: write to a temp file in the same directory, flush, then rename over the real path so readers never see a half-written file.

Large optional markdown fields were blowing up the JSON size and decode cost, so before save I dehydrate. Those strings go to separate .md files under a subfolder, and the JSON only keeps a ref key. On load I hydrate by reading those files and merging back into the in-memory map before applying it to the app.

For big snapshots I decode the file text in a short-lived Isolate so the main isolate doesn’t do a huge jsonDecode synchronously.

Secrets (API keys) are not in that JSON; they live in flutter_secure_storage.

Does this pattern sound reasonable for a medium-sized local snapshot, or would you switch to a DB (e.g. drift/isar), split files by domain, or use something like freezed + json_serializable for maintainability? Any pitfalls I’m missing (migration story, corruption, iOS backup, etc.)?

More info on the project here: r/getzoro

Got some really good feedback on this sub, so sharing a quick update here. Focused on using LLMs for data input and added a dark mode for fun. Would love to get feedback on what direction to go in next.

1. Apple Intelligence feature things like “hey siri sent think to Zoro” or using your camera to extract data from documents

2. Way to export data or share it with others to get active feedback. Maybe a human advisor in the loop type of thing

3. Agent builder to customize logic and in app execution of tasks such as updating exchange rates, auditing spending, planning for retirement

Would love to get feedback on what approach makes more sense and / or if there is anything that would make you use a tracking app over a spreadsheet.

More details, including technical info here: r/getzoro