There are other concerns but the main issue with tapatalk is the security of the forum.
At a certain point I discovered that it is exposing private data such as email addresses, password hashes/salts, etc. I figured out what's going on and fixed it. Even though I caught it early I still had to carefully audit the system and verify that the exposed info had not been accessed in any way. All was good so there was no need to alarm anyone on the forum.
This incident took some work, but most importantly it increased my work going forward. I had to do it again with every new version of tapatalk and make sure I don't find anything suspicious as well as monitor it constantly.
At this point I am simply unable to continue doing this and there hasn't been anyone else who could.