Netflix (NFLX) and Google's YouTube are two of the most prominent HTML5 adopters, but many others have also taken the leap. The Financial Times abandoned its smartphone app last year in favor of an HTML5 mobile website. The site looked and functioned like a native app -- with the advantage that FT didn't have to make changes to multiple versions of its code on multiple smartphone platforms. (Using a mobile website instead of a native app also let FT avoid paying Apple for in-app purchases.)