>>36UI is a bit like JavaFX, a bit simpler I think. it has XMLs and a visual builder. I didn't do much with it, but what I did was pretty intuitive.
IPC is inter-process communication. basically, a lot of the things in Android is done by sending 'intents' to other processes, and by receiving them. they're all about stuffing things in some kind of badly typed variadic data structure, and then manually extracting them. so imagine Java with zero type-safety. well, some things have a bit of type-safety because of automatically-generated wrapper code (basically you specify the interface in their're are 'AIDL' format and it does the dirty work for you), but don't rely on it, that's used just for one specific thing ('bound services'). everything else must do shit the hard way.