Custom Android apps in Kotlin

01What I do

What I do

1. 01

   Kotlin and Jetpack Compose

   I write native code in Kotlin and build the interface in Jetpack Compose. I keep the logic separate from the screens, so it can be checked by automated tests without a phone or device to hand, and WireAmbi has 359 of them.

2. 02

   Bluetooth LE

   I connect apps to devices over Bluetooth LE, including devices with no documentation. In WireAmbi, how to talk to cheap LED strip controllers had to be worked out without any help from the manufacturer and checked on the hardware. The app waits for the phone to confirm each command has been sent and retries any that are rejected, so none get silently lost.

3. 03

   Android Auto

   I build Android Auto screens within the templates the system allows in the car. On the car screen, WireAmbi shows a colour grid and scenes, and it recognises voice commands offline. I test the car screen in the Desktop Head Unit, Google's official Android Auto emulator.

4. 04

   Interface design

   I design the interface around where the app will be used. In the WireDrive concept for the car, that means large touch targets that are easy to hit while driving, and every car function no more than two taps from the home screen.

5. 05

   Testing on real hardware

   I test the app on a real phone and on the device it has to work with, not just in an emulator. WireAmbi works with a real LED strip controller on a phone running Android 15, and its interface is in Polish and English.

02Who it's for

Who it's for

For businesses that have a Bluetooth LE device and need an app for it, and for those that want their app to be usable in the car through Android Auto. It also suits internal tools when all the users have Android phones.

03Related projects

Related projects

• 02

  Android · 2026 · Own project

  WireAmbi — car ambient lighting from the phone and Android Auto

  An Android app for cheap ELK-BLEDOM and MELK LED strips that runs on the phone and on the Android Auto screen. The light pulses to music, and voice commands work offline. With the led-auto gateway it also shows the state of the doors and locks.

  Automated tests

  359

  From beat to colour sent

  6 ms

  KotlinJetpack ComposeAndroid AutoBluetooth LE+3

• 04

  Android · 2026 · Own project · concept

  WireDrive — a launcher for an Android head unit

  My concept for a launcher, the home screen of an Android head unit, for my Golf IV: the visual design of 22 screens, from navigation and music to car readings and parking sensors, plus an app skeleton in Jetpack Compose.

  Screens designed

  22

  Smallest button (about 1.2 cm)

  76 dp

  UI/UXKotlinJetpack ComposeAndroid+1

04Frequently asked questions

Frequently asked questions