Thing with PieFed is it don't really have an app.
There's no dedicated app, true. I find adding piefed.ca as an app via Firefox (Fennec) to be good enough, but there's two issues I have right now. One is can't sort by x amount of time for Top posts in the community although according to their repo that's in the next update, just the front page for now. The other is this comment box. For some reason the top bar of useful tools is missing unless I go to edit the same comment after posting it. Weird. Might be a bug.
Haven't tried Interstellar yet personally.
Anyways, hope your post nets you some useful options. Hadn't considered using Wikipedia for that, maybe I can add it to my RSS feeds too somehow.
"TakeOwnership Registry Hack" PSA. It just werks.