I've been developing several native mobile apps for android platform during the last 18 months. Actually i'm developing on iOS too. I used the Sencha Touch fram

I've been developing several native mobile apps for android platform during the last 18 months. Actually i'm developing on iOS too. I used the Sencha Touch framework (and their Architect tool) to build one of the apps. Here my experience: - Sencha did great efforts but HTML5 is maybe supported best on iOS than on Android so that great differences still exists between the same HTML5 app executed on Android or iOS - You have different (too much different) behaviors between android 2.3 and android 4.0 also building an html5 app - Sencha tools are really (too much) bugged for android development (this is more related to Sencha and not HTML5, but we are talking of cross platform build so it should matter) - Simply (at least for android), HTML5 app speed depends on os version but hardware too (quite obvious!): so you can have an html5 app running on a modern android4.0 device and still see lags (a lot of lags) or other problems related to HTML5...if you develop a native app, it is probable that you won't notice problems regarding performances on different android 4.0 devices, but also with not too old 2.3 devices. My experience is based on an html5 app built using Sencha 3 months ago, released for both iOS and android. I tested it on iphone4, Samsung Galaxy Note 1 and 2, Galaxy S2 and S3 so i can confirm that it is impossible to tweak an html5 app to be well performant on all these platforms/devices (so if you want to do it, you have to spend so much time that you will surely ask yourself "Maybe i should have build a native iOS app and a native Android app: i would have spend maybe a little bit more time, but i would have had reasonable return on performances and coolness of my app!"