Under inflation is terrible for longevity, handling, and safety. You should maintain proper tire pressure.

https://en.wikipedia.org/wiki/William_and_Mary_(short_story)

The android app kinda blows, as you said.

My issue with them is that they have repeatedly changed their privacy policy. They started with self hosting Matomo for analytics without announcing it, including in the changelog then went to Google again, no mention . both times they got called out, then made an announcement.