Amber is king. I also use Alby and nos2x. Peridot is looking very promising, and Aegis is the leader on iOS (although I have had a lot of problems using it). Promenade does multisig, but I haven't looked into how to actually use it — only nstart uses it to my knowledge. nsec.app is weird, works poorly on ios and is not maintained, but can be a good choice for some situations.