I've been mostly using the app, but if needed it can be done on a phones browser too, just might be a little more difficult to read. Still perfectly doable without the app.
The app is convenient but with the trouble it is causing I can see where removing it might be required.
If you choose to keep it, maybe there is a mod/admin/Etc who uses the app already that you might feel comfortable granting admin controls over the app?
What I understood from tapatalk support was if you login as an admin (I believe as an admin IN tapatalk) you can control it all.
But again... Might be too much of a pain, it depends on the apps ease of use in the admin settings to determine if it will even be worth it. It might be too complicated for just anyone to use, or it could be very user friendly. There are many programs/apps/addons out there, they are all different.
Or you might not have anyone who uses the app that you can grant admin access to(Or feel comfortable doing so).
Whatever the case may be, there's options.
I'm sure your members will go with the flow of any choice you make. =)
Also think about this... EUTM has been around longer than anyone had access through tapatalk. So it's not required to function. On the other hand, I'm sure there might be some members who signed up after seeing EUTM through tapatalk. I know of some people who asked how to join through tapatalk & I messaged them with a link & instructions because you can't Signup through tapatalk, only through the forum itself on a browser.
I'll go with whatever you choose, but I do admit to liking the convenience of the app.