Unfortunately, as libraries develop, some of them are dropping Android 4.4 and setting minimum version at Android 5.0. At least the most important library that probably makes it tricky is OKHttp, as they have for long set minimum SDK to Android 5.0. The old library version 3.12 is now deprecated as the official extended security support for it ran until end of 2021.

I'm aware that this app is generally used to make old tablets useful again and some devices still would run KitKat. However, I also wouldn't want to have the app use old unsecure libraries too long. That's why I'd rather want to see how we should best move forward. Are there still enough people using this on KitKat devices? We could also pinpoint a time, where we would definitely drop it, like stabilizing MQTT first before we cut off support for KitKat.