Building web apps is not getting easier. The fragmentation of operating systems and browsers is getting worse, not better.
Here's a chart of the past thirty days of activity at AVC.com:
No OS/browser combo has more than 17% share. And there are five with more than 10% share. iPhone is about 6% and iPad is about 4%. If you go down to the next ten combos, you find a number of Android and Blackberry combinations.
Mobile OS/browser combos in total add up to about 15% of all visits and that number is up from less than 5% a year ago.
Add in the need to build mobile apps for iOS, Android, and possibly Blackberry and you've got quite a difficult environment for developers these days.