We're sorry, but purchases cannot be restored across operating systems.
▼ Android users
As long as you use the same Google Account, you can restore the Premium Service without buying it again (for the "Monthly" and "Annual" plans, only while the plan is still valid).
Open the menu (≡) → "Premium Service" and tap "Restore" (for users who purchased before). Alternatively, choose a plan and go through the purchase; with the same Google Account you will not be charged twice.
▼ iPhone and iPad users
On iOS, the Premium Service can be restored without buying it again as long as you use the same Apple Account. See the help for the iPhone/iPad version for details.
▼ Please note: purchases cannot be restored across operating systems
The Premium Service is billed either through Google (Google Play) or through Apple (App Store). A purchase made on an iPhone cannot be used on Android, and a purchase made on Android cannot be used on an iPhone, because the payment providers are different and the system cannot restore across them.
If you switch to a device with a different operating system, you will need to purchase the Premium Service again on the new device. We apologize for the inconvenience and appreciate your understanding.