But that more or less just leads to the question: If HTML5 requires extra work to get right, isn't that what Zuckerberg was saying?
One of the big promises of mobile HTML5 was that you could just take your desktop web apps, scale them down, give them new CSS, and they'd "just work". It doesn't work that way. You need to test on actual mobile devices from the start, you need to account for the lower CPU performance of them, you need to figure in higher latency over 3G connections vs. wired LANs.
You have to do all of this on native apps anyway, but you know you have to do it from the start, otherwise you can't even get your app to display, and the frameworks are built with this in mind. There're still some areas where HTML5 wins - it's easier to update the app, for one, and it's more familiar to web developers. But the developer-convenience scales were not shifted as far to the HTML5 side as people hoped they were.
I'm still not sure which technology is, on the whole, better for mobile apps. But one of the signs that you actually understand a problem domain is that you can give advice more specific than just "Competing technology X is better than competing technology Y". We aren't going to get that in a TechCrunch soundbite; there're a lot of specifics that depend upon exactly what your market is.
This should be the actual soundbite, and it bears repeating.
If your app is a simple broacherware+notifications app, then HTML5 is probably the way to go.
If you can afford expert developers for every platform and mobile is critical to your success then 100% native makes sense.
There just isn't a simple answer here. To quote nostrademons:
I'm still not sure which technology is, on the whole, better for mobile apps. But one of the signs that you actually understand a problem domain is that you can give advice more specific than just "Competing technology X is better than competing technology Y"
If you go for a native app, you'll have to practically start over for every operating system.
- How easily can I debug things if something breaks?
- In case I'm not happy with a certain behavior is it a dead end or can I simply swap out a parameter / function / module (in that order)?
These two aspects are IMO essential for choosing any development environment if I have the choice. This goes for web development too, which is why I'd prefer something like Django over something like Joomla for example. I don't even care so much about performance at that point.
Do you agree with me that at least in case of iOS, native beats html+js+webviews in those two points?
The big downside is the one Facebook found, js in a webview is just... slow.
"It's not really that HTML5 requires extra work, it's that it lets you get away with not putting in extra work and then the lack of that work ends up biting you in the end."
I have never experienced such hard-torque spin in my life. It's not that you would need to put in overtime if you worked here. It's just that we really let you get away with never putting in overtime, if you don't want to. And then that lack of overtime ends up biting you in the end.
If you put in <x> effort into HTML5 you'll have a slow, shitty version. If you put in <x+y> you'll have a nice fast version.
If you put in <x> effort with a native app, you have nothing. If you put in <x+y> you have a working, fast app.
You get a working prototype faster with HTML5, but that's not a fair comparison with a native app which took more work to get working at all.
It's not just that JavaScript is slow, although that doesn't help - having to worry about the performance implications of using libraries rather than directly using browser APIs, or being forced to use native scrolling because JavaScript scrolling just can't avoid lag, is a waste of time. It's also that where native UI frameworks are designed for performance from the start - every single UITableView is drawn lazily (implementing "immediate-mode" infinite scrolling on top of the deferred mode DOM is awful), you can fluidly move between low-level and high-level drawing APIs (Canvas is a very sharp boundary), animation feels built in rather than a recent hack (and I hope you're not targeting anything other than WebKit) - in HTML you have to fight against an absurd layout system to do anything and, in some sense, work around it to do anything fast; there are usually many ways to do it but most of them are slow.
And it doesn't help that where native frameworks have built-in controls to do a lot of things - and those controls look and feel native simply because they have the home field advantage of being what everything else has to mimic - HTML5 is left with a bunch of shitty webapp frameworks and the option of reimplementing everything yourself. The creators of those frameworks seem to assume things like if the animation looks vaguely like the original, there's no need to actually get the details right to avoid uncanny valley, or make it performant at all, so you probably want to make it yourself. I hope you know what you're doing.
As much as I love HTML5, you have to fight every step of the way to make something that works right. Getting a prototype out is easier with HTML5 than native, but for a moderately complex app, making it actually work right is vastly harder.
(I do like the better layout systems and widget libraries of native frameworks - I did desktop app development with Swing and MFC before HTML/JS, and it really was significantly easier to put together a complex UI that matches the native look & feel with those. HTML5 gives you the opportunity to be creative that you don't have when you overrely on a framework, though.)