I just bought Purify today to eliminate ads on the iPhone. I'm loving it so far. Best $2 I've spent in s while. I'm just done with the pop up ads, re-directs, screen space grabbers, etc.
There is a level on the built in compass app as well.In addition to many of the above, I use Spirit Level Plus to level my motorhome.
Sorry, I meant on the iPhone.I don't think my G S III has a built in compass. I'm sure I could find one though.