Locking the apartment building exit door is illegal under Czech fire code, in case of fire EVERYONE in the building (which can be also visitors not living there) must be able to open door from inside even without key or anything. That's the law, reality without enforced law is different, so you can easily get stuck in front of the door with fire behind you.
https://www.hzscr.cz/clanek/zamykani-vchodovych-dveri-bytovy...
As for apps, haven't seen it anywhere, we use chip keys, but almost always there is also standard key lock available.