If prefer to pay a monthly subscription, tap BILLED EVERY MONTH, and tap NEXT.If prefer to subscribe to Revo Uninstaller Mobile for an entire year, leave BILLED EVERY YEAR selected, and tap NEXT.If you had decided to purchase a subscription, or you already have a serial number (key), the third screen will allow you to select the subscription type or enter your serial number to unlock the PRO functionality: If you prefer to stick to the freeware (ad-supported) version for the time being, tap CANCEL. If they appeal to you, and you would like to purchase a subscription, or you already have a serial number (key), tap GET PRO. The second screen will give you an overview of the benefits of the PRO version of Revo Uninstaller Mobile. When you first launch Revo Uninstaller Mobile, you will be greeted with a welcome screen. If you do that on your computer, you will be prompted to select the Android device, on which you wish to install the app. Simply tap the Install button in the upper right corner. You can download Revo Uninstaller Mobile products from the Google Play Store