By modern standards, the official App Store on iOS 5.1.1 is practically non-functional, serving "Unsupported Device" errors for almost every application. To turn your vintage device into a functional retro-gaming machine, an e-reader, or a dedicated media player, you must rely on sideloading .ipa files.
: For a more stable experience, jailbreak the device and use tweaks like Checkmate, Store! which helps bypass compatibility errors in the App Store, or AppSync Unified to run unsigned IPAs. Top Legacy Apps & Games ipa ios 511 2021
By 2021, the official Apple App Store had systematically dropped support for older 32-bit applications. If you attempt to access the App Store from a stock iOS 5.1.1 device, you will likely encounter connection errors, or find that 99% of available apps require iOS 10 or higher. Retro Gaming and Utility By modern standards, the official App Store on iOS 5
Navigating iOS 5.1.1 IPAs in 2021 and Beyond: The Ultimate Legacy iOS Guide which helps bypass compatibility errors in the App