OBS Controller is a free Android app developed by Erik Fahlén that allows users to switch scenes in OBS with ease. It is a simple app that focuses on providing users with a mobile scene switcher for OBS. The app works out of the box with OBS v28 and above, but for earlier versions, users must install the obs-websocket plugin. The app allows users to hide scenes they don't want to accidentally switch to, control their stream, recording or virtual camera output, show/hide individual scene elements, and mute audio sources. Additionally, users can configure a delay for the commands in case they want to sync scene switches with camera delays.

Overall, OBS Controller is a great app for anyone looking to have a simple and easy-to-use mobile scene switcher for OBS. The app is user-friendly and provides a great experience for users who want to control their OBS scenes from their mobile device.