It sends telemetry data to about 30 companies. Pretty standard for Google Play tracking and it's not possible to know if the data is being taken advantage of or not.
It's good to be cautious of that. But if you're completely offended by that or if you're completely accepting of that, you should consider the situation better.
It's a new Lemmy mobile app that is a port of one of the most popular Reddit 3rd party apps, and has one of the cleanest UIs. Sync for Lemmy feels just like Reddit did for people who used Sync for Reddit, and people are nostalgic for it. Sync fans are stoked to have their old app back, but tech nerds are mad that the app is not FOSS (free, open source software) like many other Lemmy apps, it has ads, pricey in app purchases, and sells user data