I did some digging around, and here's what I found.
1. Posting and browsing seem to work fine on Android. I installed it on my own phone just to confirm.
2. Apparently one of the updates to the client app (not the mod on our end) has introduced a bug that causes the crash when posting. Until they patch it, the only fix is to downgrade versions, presuming you have any way of doing so. Example of someone talking about said bug (and, of course, finding some way to involve politics in it) here...
http://www.rdforum.org/showthread.php?t=40985
3. What Johann said is correct. Tapatalk is currently focusing their development on PHPBB 3.1, which is good news for us. But as of right now, the mod on our end does not include a feature for PMs.
https://support.tapatalk.com/threads/no ... ges.27212/
https://support.tapatalk.com/threads/ta ... #copyright
On that last one, look for the post that includes the phrase, "Features that have yet to be implemented but are incoming for future releases..."
4. Tapatalk is terming anyone using PHPBB 3.1 as "early adopters". Go fig on that. Either way, it looks like we're stuck waiting on them for both the client app and server mod.
5. In the meantime, as Maniah said, the PHPBB 3.1 templates are much more mobile-browser friendly, so you might want to give that a try.