There is no upgrade path from AllOnMobile v3.x to v4. Mobile Devices with AllOnMobile v3.x installed and automatic updates enabled will not be asked to upgrade to AllOnMobile v4. AllOnMobile v4 must be installed from the devices App Store.
AllOnMobile v4 is available from:
Google Play Store
Apple App Store
Microsoft App Store
Simply search for ‘AllOnMobile v4’, and make sure you have the new AllOnMobile blue logo.