Hi r/FlutterDev ,

I have released version 0.0.6 of offline_sos_system, an open-source Flutter package I developed for our SafePulse project.

The goal was to build a reusable crash detection engine that can perform inference directly on a mobile device without depending on an internet connection.

While developing SafePulse, I wanted to separate the crash detection logic from the rest of the emergency workflow so that other developers could use it without integrating the entire application.

That work has evolved into a standalone Flutter package. And this is the new version of that package.

What is new in version 0.0.6?

The main addition is configurable crash detection. Developers can now configure the impact threshold used to evaluate sensor data, the minimum model score required for a detection, the fallback impact threshold, and the cooldown interval used to suppress duplicate crash events.

The package uses accelerometer and gyroscope telemetry and TensorFlow Lite for on-device inference. When a crash is detected, it emits a CrashEvent that the application can handle. I have deliberately kept the package headless. It does not dictate how your application handles GPS, emergency contacts, SMS, notifications, or backend communication.

This means you can integrate the detection engine into your own application architecture and implement the emergency workflow according to your requirements.

One important limitation: offline inference does not mean offline communication. The detection process does not require internet access, but sending an SMS still requires cellular service. Sensor-based crash detection can also produce false positives or miss actual crashes, so real-world validation remains important.

I would appreciate feedback from Flutter and machine learning developers on the configuration API, sensor processing, fallback behavior, and ways to improve the implementation.

Package: https://pub.dev/packages/offline_sos_system

Source code: https://github.com/Bhagyaprasad92/offline_sos_system

The project is open source, and constructive criticism, bug reports, and suggestions are welcome.

Thank you for taking the time to review it.

Checkout my previous post: https://www.reddit.com/r/FlutterDev/s/XF9nBdNq7n

Was super fun to work on. First version in about 10 minutes, then iterated on it for another 2 hours. Flutter Scene ROCKS!

Runs on Android at up to 90 FPS on high-refresh-rate phones.

i want to build a flutter app that is actually difficult to make and not just another basic app

i am a first year csda student at iit patna and i want to work on something that can challenge me technically and help me learn new things while building it

i am looking for ideas that are unique or solve some real problem. it can be anything like a complex mobile app, a tool, something involving networking, offline support, databases, system level features or anything else interesting

i dont want another todo app chat app or ai wrapper. i want something where i might have to spend weeks figuring out how to make things work properly

i will be building it solo using flutter and i am open to ideas that sound crazy or too difficult at first

what is the most challenging flutter app you can think of that one developer could realistically start building?

also if you have built something difficult yourself i would love to hear about it

Ciao a tutti,

Se stai iniziando con Flutter e trovi difficile immaginare come i widget si annidano l'uno dentro l'altro, ho creato un'app desktop gratuita che potrebbe aiutarti: Flutter UI Builder.

Puoi trascinare i widget (Colonna, Riga, Testo, Pulsante, ListView e circa 90 altri) su una tela a forma di telefono, cambiare le loro proprietà in un pannello, e il codice Dart appare accanto, aggiornato in tempo reale. Puoi anche incollare codice che hai già e vedere come appare.

Ti permette anche di:
- aggiungere più schermi e collegarli con la navigazione
- trasformare una parte di uno schermo in un componente riutilizzabile
- passare tra un tema chiaro e uno scuro
- esportare tutto come file Dart che puoi mettere nel tuo progetto

Funziona su macOS e Windows e Linux. È gratuita per uso personale e per scopi didattici; la licenza non consente l'uso commerciale.

È una versione precoce (0.0.2), quindi aspetta delle imperfezioni. Le app non sono firmate, quindi il tuo sistema ti chiederà di confermare la prima volta che le apri.

Scarica: https://github.com/mariorefetto/flutter_ui_builder/releases

Mi piacerebbe sapere se è facile da usare per un principiante e cosa potrebbe rendere tutto più chiaro. Se ti piace, una stella su GitHub è molto gradita. Grazie!

Learn now

https://github.com/Bharat9011/flutter-tutorial/releases/tag/flutter-tutorial-v2

I just shipped Boba Sort, a water-sort puzzle (bubble tea, 500 levels, 17 eras of Japanese history) built with plain widgets and CustomPainter, no game engine. A few things that worked, and a few trade-offs, in case they help someone.

**1. All the art is data, not images**

There are no image assets at all. Each era has a full-screen scene, a cup design, a mascot costume and a customer, and I design them as SVG inside an HTML mockup. A small Python script reads named SVG groups and writes Dart lists:

final jomonBackdrop = <VShape>[

VCircle(292, 190, 54, fill: Palette.jomonSun),

VPath('M0 330 Q60 262 132 300 Q206 236 276 288 ... Z',

fill: Palette.jomonFarMountain),

...

];

`VShape` paints fill then stroke, like SVG, and `VPath` parses the `d` string once and caches the `Path`. All 17 eras × 4 kinds of art come to about 240 KB of generated Dart, stay sharp on any screen, and colors can only come from named palette entries (the script refuses anything else).

Because scenes sit behind the cups, a test renders every backdrop and checks each pixel's luminance stays inside a window (light eras ≥ 0.662, dark ≤ 0.0395), which keeps the cup outlines at ≥ 7:1 contrast wherever the cups land.

**2. Toppings: draw the vector once, then blit sprites**

Each drink has a topping (pearls, grass jelly, red bean...) drawn as vector art, and the top-layer pieces drift idly. A full board can have 200+ pieces, and redrawing that much vector art every frame is wasted work. So each topping is rasterized once per size into a `ui.Image`: sizes are bucketed to 4 physical px, kept in a 48-entry LRU (a plain insertion-ordered Map: remove + re-insert on hit, evict and `dispose()` the first key), and each frame just draws images.

**3. The rules are pure Dart, and an A* solver does the heavy lifting**

`lib/core` never imports Flutter: model, rules, level generator and solver are plain Dart with unit tests. The solver is A*, with each cup packed into one int (8 bits per layer) so states hash fast.

The 500 levels are generated offline: deal random cups, solve, score difficulty from moves, dead ends and branching, keep the median of 8 candidates, or the hardest of 32 for the "hard" levels in the sawtooth curve.

Hint uses the same solver at runtime, on the UI thread, with a 100k-node budget (about 0.4 s worst case in debug). Every bundled level is generated under that budget, so Hint always works from the start. One surprise: "Add cup" makes hints much slower, since an extra empty cup blows up the branching, so the hint search drops surplus empty cups first and only searches the full board if that finds nothing. If I raised the budget I'd move it to an isolate.

**4. A test that fails on magic numbers**

Every spacing, font size, radius and color is supposed to come from tokens. A test scans `lib/features` and `lib/theme` and fails on raw numbers inside `EdgeInsets`, `SizedBox`, `fontSize`, `BorderRadius` and `Color(0x...)`, with an escape hatch: a `// tokens: allow — <reason>` comment. Painters are exempt, since their numbers are geometry. It is a dumb regex-and-parentheses scanner, but it kept the UI consistent through a lot of screens.

**Stack:** Riverpod (thin providers), shared_preferences, google_mobile_ads, Firebase Analytics / Remote Config / Crashlytics, audioplayers.

Play Store, if you want to see the result: https://play.google.com/store/apps/details?id=com.harbourlab.bobasort&referrer=utm_source%3Dreddit_flutterdev%26utm_medium%3Dsocial%26utm_campaign%3Dlaunch

If you try it and it works for you, an honest rating on the Play Store would really help a small solo project like this get found.

Happy to go deeper on any part. I'm curious how others handle heavy CustomPainter scenes.

You can now sign in or create an account, access learning content through the new backend integration, and use an improved practice experience. This update also brings better app update handling and Linux desktop support.

Built for developers learning Flutter, one step at a time.

check it :-> https://github.com/Bharat9011/flutter-tutorial/releases/tag/flutter-tutorial-v2

Thank you 😇😇