The app is called Forum Runner.
#1. The free version does everything Tapatalk does and more, downfall is you can't post attachments.
#2. The Dev himself told me that in the paid version you'd soon be able to add your favorite unlisted forums.
So should you try? Yes.
I didn't post attachments when I had Tapatalk because the quality had become shot out.
Give a go.
Send from RushDroid 3 using Forum Runner