Every app shell needs to be updated periodically to target the latest versions of Android and iOS. Apple and Google require apps to keep up with their newest OS releases, and an app that falls behind may become unavailable to people on those versions. Rock and Rock Mobile each release about two major versions per year, so plan on a shell update at least once a year to stay current, available on the latest devices, and covered by the latest security fixes. Outside of OS requirements, older shells generally keep working as you update Rock. Some new features do require a newer shell version, so check the release notes when you upgrade Rock. Match Your Shell to Your Rock Version We recommend keeping your app's shell version at or below the version of Rock on your server. Each shell release is built and tested primarily against its matching version of Rock, so the best time to request a shell update is after you upgrade Rock. Running a shell that's newer than your Rock server isn't something we officially support. It will often work fine, but some features may depend on a newer version of Rock, and issues that only occur in this setup may not be prioritized. Android https://support.google.com/googleplay/android-developer/answer/11926878 Every year Google updates Android with a new version and underlying API level. The Rock Mobile shell targets an API level and is updated periodically as those become available. Google's policy is that existing apps must target the latest major Android version's API level within two years, or that app won't be available to new Android versions. To put it simply, your Rock Mobile app on Android needs a shell update published to the Play Store at least once every 1-2 years, but an annual cadence is recommended.