Ime many “bad” reviews are from people who don’t know what they are doing. The apps are ok, but every phone mic has a different roll off so I don’t trust them totally. Many are free though...
Umik/rew is the best, but more expensive. The ol trusty radio shack meter is ok. Not sure about newer ones, as I use rew or my RS meter, but I’m sure for the twenty or thirty bucks, it will do what you need.