Calculator++ has been my favorite so far. Previously I had been using either the google packaged or an open source that had widget functionality, but++ opens as widget size and they buttons are actually reoaponsive at that size.

Libre Camera is what I switched to after simple got sold. I don't use the camera app enough to really have an opinion. My biggest complaint is that my bottom row of essential apps no longer have the same design style or coloring.

Still using simple calendar. Probably going to wait until the fork comes out and switch to that, or may just use proton's calendar. I remember I didn't like theirs. Possibly because it either didn't have a widget or I didn't like their widget. I don't remember which.