In order to use the Windscribe VPN on an Android mobile device, you need to be running Android 5.1 or above. However, there are certain feature and options that are only available on higher versions of Android.

For instance, the ability to automatically reconnect in the event of a device restart via Auto-connect on boot feature requires Android 9 or above. In addition, the Always-ON VPN function requires Android 8 or above.

If you are unsure about the specifics of your Android device, have a look at this help article: https://support.google.com/android/answer/7680439?hl=en