I can’t find a good WIFI analyzer for IOS. Can someone shoot me a recommendation?

I’m a field tech 1 for an isp and would like to familiarize myself with a WIFI analyzer. I’ve seen many techs use them and figure it would be a good way to optimize WIFI set up.

I haven’t been able to find a good free version to use on my iPhone. I’m willing to pay for It, I just want to make sure I pick the right one.

Thanks