Well, I've personally got f-droid, newpipe, both Facebook lite and messenger lite as I was not able to install them based on where I live through the play store. Both of those are far better on battery life, and messenger lite lacks ads. I also then use f-droid to install as many apps available both there and the play store as I can because I prefer to avoid Google's services as much as I can. I use apkmirror sometimes to get older versions of apps if i dislike the updated one.