Polku Trail Tracker
An offline-first hiking app with GPS tracking, downloadable topo maps and battery-aware location sampling. Rewritten from XML views to Compose with a 38% faster cold start.
- Compose
- Room
- Maps SDK
- WorkManager
Downloads250K+
Seinäjoki Arcade presents
Native Nights
Stage 01
Player Select
1P · Kotlin class
I build Android apps that feel fast, fluid and native — from the first frame to the millionth install.
I'm Janne Heinonen, an Android developer based in Seinäjoki, Finland. For the past eight years I've been shipping Kotlin apps for startups and established product teams: consumer apps, field-service tools and connected-device companions that people rely on every day.
My focus is clean architecture, Jetpack Compose UIs that stay smooth at 120 Hz, and offline-first data layers that survive real-world networks. I care about cold-start times, accessibility and test coverage as much as pixel polish, and I enjoy mentoring teammates through code reviews and pairing.
8+Years in play
20+Apps shipped
4.7★Avg. rating
Stage 02
Power-Ups
Stats maxed outLV 10
LV 9
LV 9
LV 8
LV 8
LV 8
LV 7
LV 6
Inventory
KotlinJavaJetpack ComposeCoroutines & FlowHilt / Dagger
Retrofit & OkHttpRoomWorkManagerNavigationMaterial 3
Gradle KTSGitHub ActionsFirebasePlay ConsoleBaseline Profiles
Wear OSGraphQLFigma
Stage 03
Stage Select
Choose your levelSaunasense Companion
Companion app for a smart-sauna controller. Bluetooth LE pairing, live temperature & humidity graphs, remote preheat scheduling and a Wear OS tile.
- BLE
- Wear OS
- Flow
- Hilt
Crash-free99.8%
Kassa POS Terminal
A Kotlin point-of-sale app for small retailers running on rugged Android terminals: barcode scanning, card-reader SDK integration and sync that tolerates hours offline.
- Kotlin
- MVI
- Room
- CameraX
Stores1,200+
Stage 04
High Scores
Career leaderboard| Rank | Role | Years |
|---|---|---|
| 1ST | Senior Android DeveloperNordic mobility & outdoor-tech studio
Lead developer on a team of five. Drove the Compose migration, introduced modularisation and Baseline Profiles, and cut ANR rate by 60% across three flagship apps. |
2022 — Now |
| 2ND | Android DeveloperIoT product consultancy
Built Bluetooth LE companion apps for connected home and wellness devices. Designed a reusable BLE connection library and CI pipelines with automated Play Store releases. |
2019 — 2022 |
| 3RD | Junior Mobile DeveloperRetail software agency
Developed point-of-sale and loyalty features in Java and early Kotlin, wrote the first UI test suite and supported production releases for regional retail clients. |
2017 — 2019 |
| 4TH | B.Eng. Software EngineeringUniversity of Applied Sciences
Thesis on energy-efficient background location on Android. Google Associate Android Developer certified. |
2013 — 2017 |
Stage 05
Continue?
Player 2 may joinJanne Heinonen
Android Developer
- First name
- Janne
- Surname
- Heinonen
- Address
- Vainolankatu 7
60120 Seinajoki
Finland - Phone
- +1 262 332 0180
- yunbarlip6@gmail.com
Credits: ∞