I just found out about this app a few days ago and it might be my favorite one ever. Every day it has four puzzles about a specific subject and at the end it gives you really cool information. It makes me feel so smart and it's the perfect thing to do while doing my morning coffee. And the best: it has no ads and it's almost all free! The only thing you could pay for it you want it's the access to their past puzzles. I've been so annoyed with apps recently because they're always so expensive and they're free versions are totally unusable but not this one.