I LOVE TelemetryDeck! I’ve been using it since it was in beta in my apps, and it’s been fantastic throughout. It’s very simple to use and the support (which I very rarely need!) is great too.
My favourite thing is the iOS widgets. I have a stack set up so I can see graphs of my daily active users across all my apps.
I also love the company ethos of being privacy first. Until TelemetryDeck I didn’t have any analytics at all for fear of invading my users’ privacy with a big black box package like Firebase. TelemetryDeck is a tiny package that doesn’t do anything creepy in the background.