I’ve got a ‘port’ of NextCloudPi running on Android inside a Linux Deploy container. All you need to get started is a rooted Android device from around 2013 or later. Form factor is unimportant; it could be a phone, tablet, HDMI stick, TV box, toaster, or any device running Android.
I started off with the ‘stock’ NextCloudPi installer (install.sh) and massaged it to run error-free, created new SysV initscripts and made a bunch of other fix-ups to account for differences in Android’s Linux behavior as compared to a stock Linux distribution.
Many ARM-based devices are becoming hard to come by due to supply chain woes so Android could serve as an interesting alternative. Folks wanting to buy a single-board ARM computer may already have a perfectly usable one nearby just gathering dust in a desk drawer somewhere.
If your Android device has a battery and was unused for months or years, replace its battery. Old, worn, or abused Li-ion batteries can fail when pushed back into service. Failure appears as a bulge in the battery, or worse a “thermal event” - Replacing it essentially serves as a UPS for your device.