Disclaimer for this post: I worked for ~2 years as a privacy reviewer for infra services at Google. This is what I would minimally declare for the Mastodon app, from my reading of Apple's policy:

- Contact Info (email address, obviously)
- Location (coarse location, Mastodon stores IP addresses in logs)
- Contacts (your follows/followers)
- User Content (your toots)
- Search History
- Identifiers (handle)
- Usage Data (logs, anti-abuse)

Not far from Threads' list...