Starting with the upcoming version 5.9 Release, which is currently slated for December, the minimum device requirements to play MARVEL Strike Force will be iOS 11 for iOS devices. Versions of iOS older than iOS 11 will no longer be supported, and to avoid any disruption to your playing experience, we recommend updating as soon as possible: https://support.apple.com/en-us/HT204204
For Android devices (and all devices in general), we recommend a minimum of 2GB of RAM as playing with less may cause performance issues.
If you're playing MARVEL Strike Force with a device that isn't supported or doesn't meet our technical recommendations, you'll begin seeing an in-game warning pop-up starting with the version 5.7 Release. You'll have a little over two months to update your device, so please do so to avoid interruptions to your gameplay.