Altimeter GPS & Barometer

My main concern was about the altimeter because I have a hard time to go up high. However this app has way more than I expected and I’m enjoying it.

This app does not work on my iPhone 12. I tried reinstalling it several times. I thought maybe it was my phone that was defective so I downloaded and tried to use this app on my friend’s iPhone 14. I got the same non-working result, i.e., when I tap on the app icon, the app begins to load and then a screen comes up with a continue at the bottom button when I tap the continue button I get the home screen. This happens on both my iPhone 12 and my friend’s iPhone 14. I tried using the app in Seattle Washington, and also in Washington DC with the same nonworking result. I now think it is a problem with the app not with the phones.