HTML5 is going full-steam ahead with the browsers competing to add features and improve implementations. But, HTML5 on mobile is still a huge pain in practice,

HTML5 is going full-steam ahead with the browsers competing to add features and improve implementations. But, HTML5 on mobile is still a huge pain in practice, if you want to go beyond a basic content app. e.g. you can't do anything in the background or triggered by alarms/geofencing type events, can't do notifications or widgets, graphics/multimedia can be slow, even basic UI components like fixed nav-bars have buggy implementations. It's still great to use HTML5 to build a fully functioning web presence across devices. And HTML5 on desktop is very solid now as a full-featured application platform. I wouldn't say adoption is slowing down in absolute terms. It's just that it's not reached its full potential as many of us had anticipated a couple of years back, because it's not (yet) a viable implementation choice for most mobile/tablet apps.