The data the trackers can gather is more restricted but the principle remains the same. I've installed various of different kinds for my customers. Most of them

The data the trackers can gather is more restricted but the principle remains the same. I've installed various of different kinds for my customers. Most of them are simply tracking what users do in an application to see how they can be improved but I've seen an app that uploaded your whole contacts book immediately (when it was still allowed, not the case anymore). I'm not too much in the know about Android permissions. I know it improved a lot lately but I think still some permissions are still accepted silently on install. Gathering data about the movements of your users within your application can really be helpful, I draw the line where things get shared with third parties or excessive data is gathered.