For iOS, the largest screen size you can use is the 12.9 inch iPad Pro variety. Any iPad model will work as long as it can run iOS 16.6 or higher. You can use this article from Apple as a reference for which models those are: https://support.apple.com/en-us/103267
We have an Android beta version of KioskBuddy available for download here: https://play.google.com/store/apps/details?id=com.kioskbuddy. Android offers a wide array of screen sizes, the only requirement is that the device runs Android 12 or higher. We’re currently not affiliated with any hardware providers, so we aren’t able to make direct screen recommendations.