Sorry I haven't had time to work on it for a very long period, but I haven't abandoned it
There's no major issues with the current version so any planned changes are really to support additional feature requests (like android tv) and any bugs that come up.
I will be moving over to the latest Hatari source at some stage, but it will be a completely new app since it uses a different cpu core that currently doesn't have the same performance level as the old core (so is more suitable for newer android devices).
I think you should try to find someone with an android device and try it out before you buy a tablet to see if it's something you like using.
I've only used it up to Android 7, but good to hear that it works with 8.0 as well.