What are the system requirements of the program?

Android 5.0 (API 21) and above.

What is the difference between Basic and Premium version?

The “Premium” version enables such features:

What will happen if I will change my device?

When you purchase Tilla Premium, in Google Play, it will be assigned to your Google account. If you use the same Google account on a new or factory reset device, you will have access to all previous purchases.