In response to Mueller-ma seeking long games => try Sokoban, Chess, Chess variants ^^
An update of an VOIP app would be great, given that Android proper seems to treat these rather negligant. As csipsimple seems to be dormant, I would love to see the current version of linphone being integrated.
A keyboard allowing swipe typing.
(Also, a worthy Dropbox Paper alternative, but I don't think that's coming anytime soon.)