Flutter Apps With VULK: Live Preview and a Signed Android APK

Verified on October 10, 2026, against the code VULK runs today and its production build records.

Ask VULK for a phone app and you get a Flutter project, not a website squeezed into a phone frame. You can try it in the browser while it is being built, and when you are happy, ask in the chat for the Android file and install it on your phone.

The short version

Real Flutter, compiled for the preview

The preview is not a mock-up. VULK compiles your app with Flutter's own web build on our servers and checks it with a headless smoke test before you see it. The Flutter engine for the preview loads from VULK, not from a third-party CDN. A compile can take up to six minutes, and a finished preview build is kept for 24 hours, so reopening a project does not rebuild it every time.

When you edit, VULK works out which Dart files your request affects and changes those, instead of regenerating the whole app.

Designed, not stock Material

Until recently, generated Flutter apps looked like Material defaults in the right colours. Since October 10, 2026, every app with a design gets a visual kit compiled from that design, in code rather than by a model. It includes raised and glass surfaces with soft shadows, photo cards, a hero image that fades into the page, pill buttons, stat rows and a floating dock in place of the stock navigation bar. Each app also gets its own signature colour, atmosphere and navigation form, and a palette that fails a contrast check is moved to the nearest colours that pass instead of being refused.

Two smaller things matter more than they sound. The fonts of your design ship inside the app, so the APK never falls back to Roboto or fetches a font at runtime. And the name you give the app is the name under its icon on Android.

Full-stack Flutter

A Flutter project can be generated for the same managed backend as VULK web apps: its own PostgreSQL database, user accounts and REST API. VULK generates two Dart files for it, an API client and a data layer, and the preview in your browser talks to that backend.

The APK: how you get it

In the chat, ask for the APK. VULK starts a build from the exact files that were delivered, and a card in the conversation checks the build every 10 seconds until it turns into a Download button.

A request that only asks for the APK does not touch your code. It builds the app you already have without running the code writer. The build itself charges no credits.

Each build runs flutter create . --platforms android on a Linux build service and then compiles your code into it. The APK is signed with a key kept for your account, or with your own keystore if you upload one in the app signing settings. When you edit the app and build again, the new APK keeps the same Android package name, so, signed with the same key, it installs as an update over the old one instead of as a second app. Android refuses an update signed with a different key, so if you switch from the account key to your own keystore, remove the old app first.

The file is stored in a private bucket and downloaded only by the account that owns the project. Every stored APK carries a SHA-256 digest, checked again when it is read.

Measured: how long, how big

From our production build records, read on October 10, 2026, for builds between September 26 and October 7, 2026:

Phone features

VULK apps can use real device features in the preview: maps (flutter_map 8.1.1), location (geolocator 14.0.2), the camera and photo picker (image_picker 1.2.3), PDFs (pdf 3.12.0), the share sheet (share_plus 12.0.2) and local notifications (flutter_local_notifications 19.5.0). These go through doors the compiler writes, so the model never invents native code.

Plans

Every paid plan can build APKs, because a build counts as exporting your code. Builder includes five mobile builds a month; Pro, Max, Team, Business and Enterprise have no monthly cap. Prices are on the pricing page: Builder $19.99 a month, Pro $39.99 and Max $199, read on October 10, 2026.