According to the tracking scanner Exodus (can be found on F-Droid), which keeps an updated database on trackers and runs your installed app against its register, you can track what apps are tracking you and clues of how. Saw that Boost is tracking me and uninstalled it and went straight to Jerboa. Jerboa is pretty similar to good ole’ RedditIsFun-app and easy to use, so I am personally recommending it.
From F-Droid:
Exodus (Exodus show you trackers and permissions in apps installed on your device.) https://f-droid.org/packages/org.eu.exodus_privacy.exodusprivacy/
Mlem is in my opinion the best open source Lemmy client for iOS. There is another amazing client named Arctic for Lemmy that has great UX but the app is proprietary. However it seems to be privacy respecting and nothing compared to Boost privacy nightmare on free tier.