@TheDragon @nbourdais Sounds like #SailfishOS could fit this, indeed. You probably don't need the Android app support, so the free SailfishOS community edition would suffice. And you could use one of the many community ports, enlarging your available device range. I remember SFOS being quite snappy even on the slow #Pinehone 1. SailfishOS is very much #LinuxMobile. The UI is proprietary though. There's #nemoMobile as alternative, but I have never tried it.