With Nostr it's also a good idea to have a custom follow list. For example I have a list called "Home" that has only something like 13 people that only post deeper thoughtful content that I enjoy - like nostr:nprofile1qy2hwumn8ghj7mn0wd68ytndv9kxjm3wdahxcqg5waehxw309ahx7um5wfekzarkvyhxuet5qqsw4v882mfjhq9u63j08kzyhqzqxqc8tgf740p4nxnk9jdv02u37ncdhu7e3 ). Amethyst supports custom lists.

A cool little app is Habits - essentially set some goals and have widgets on screen to quickly mark that you did the goal each day.

Another app could be book reader: I enjoy reading books on my phone, so app like Moon+ reader (it has paid version, but I really like it). Not sure if this fits your definition.

Get good music app for offline music and load the phone with a bunch of music you like. I like Shuttle.

Get podcast app if that fits your definition - AntennaPod is now surprisingly good.

And then obviously set up way to pay with bitcoin, so e.g. Phoenix and Coinos web app (for zaps)