Xamarin and Qt are very different. Xamarin provides a managed runtime environment (Mono) and a way to call native iOS and Android APIs from that environment. X

Xamarin and Qt are very different. Xamarin provides a managed runtime environment (Mono) and a way to call native iOS and Android APIs from that environment. Xamarin Forms builds on top of those things to provide a cross-platform UI toolkit that uses the native controls on each platform. Qt is a cross-platform GUI toolkit that draws its own controls using each platform's low-level graphics facilities. As such, the controls in a Qt-based application aren't fully native to each platform. Qt tries to mimic the native controls, but the emulation isn't completely faithful. A particular problem is accessibility for users with disabilities, e.g. blind users who need to use a screen reader. Last time I checked (several months ago), Qt didn't implement the accessibility APIs for iOS or Android at all. Because of the non-native nature of Qt, I would strongly recommend avoiding it in favor of something like Xamarin or RubyMotion.