Best open-source Kotlin projects

Open-source Android authenticator app for generating TOTP and HOTP two-factor codes, from the makers of 2FAS.

Android image editor app offering dozens of tools, from crop, filters and drawing to OCR, background removal, PDF tools and AI upscaling.

Android app that scans nearby Bluetooth Low Energy devices, analyzes their broadcast data, and alerts you to suspicious or following devices.

An Android app that screens incoming calls and SMS messages to block spam without replacing your default phone or messaging app.

Android firewall that blocks per-app network access without using a VPN, driven by Shizuku, local ADB or root.

An open-source multi-system game emulator for Android, built on Libretro, covering consoles from NES to PSP and Nintendo 3DS.

An on-device Android app that turns websites, HTML projects and server runtimes into installable, signed APKs without a PC.

A rootless Android app that boots a real Alpine Linux VM so you can run Podman, Docker and LXC containers and GUI Linux apps on your phone.

Android and iOS app that scans for nearby Bluetooth LE signals from smart glasses (mainly Meta Ray-Ban) and sends a warning.

A free, open-source Android app that lets you manage your phone's files, messages, calls, and screen from a web browser on the same network.

Android app that runs PC games from your Steam, Epic, GOG and Amazon libraries locally, with cloud saves, without streaming.

A desktop GUI for Android app testing with ADB, supporting device listing, shell commands, text input, screenshots and virtual displays on Windows and macOS.

An Android, Windows, macOS and iOS chat assistant that judges the other person's intent and risk first, then drafts replies for you to send.

Local, offline file converter for Android covering video, audio, image, PDF, Office, font, and subtitle formats, with no uploads or ads.

Offline Android PDF editor that merges, splits, compresses, converts, annotates and signs PDFs entirely on-device, with no internet permission.

An Android app that downloads apps and applies ReVanced patches to customize them, built on the ReVanced Patcher.

A customizable, offline-first document and e-book reader for Android, Linux and Windows, built with Kotlin Multiplatform and Compose.

Android app that turns a phone into an SMS gateway, letting you send and receive SMS and MMS through an HTTP API or CLI.