To JAC teacher:
I believe the problem you are experiencing with Tap it stems from the new feature called Multitasking Gestures introduced with Apple iOS. You may experience Tap it issues if you have multitasking gestures turned on for your iPad. Multitasking gesture allows you to use 4 or 5 fingers to reveal the multitasking bar, pinch to return to the home screen, and to swipe left/right to switch between apps.
Please follow the steps below to try and get it working:
1. On your iPad, open the Settings app, click General on the left, and then scroll to Multitasking Gestures on the right.
2. Toggle Multitasking Gestures to OFF.
3. Launch Dexteria > Tap it to see if it is functioning again.