I just published an update on the Play Store. The main change is that you can now get lives back after a certain amount of time. Here’s the full change log:
Number Crunchers Version 1.01
* Removed unnecessary permissions.
* Removed interstitial ads from appearing after a number of levels.
* Added timed Extra Life option.
* Added timed Extra Life after video viewing on Free version.
* Added video viewing after a number of levels in Practice mode on Free version.
* Added Main Menu button on Goal Selection menu