Convertigo, RubyMotion, B4X, WebDGap, Appcelerator Titanium, Apache Cordova, Sencha Touch, MyEclipse, MobBase, AppFlight, RhoMobile, Kurogo Mobile Platform, Capacitor by Ionic, AppArchitect, Codename One, Airplay SDK, Calatrava, MoSync are some alternatives to MonoTouch.