I had the pleasure of working on the iTRAK® WebApp over the past several months: http://www.gpsworld.com/itrak-webapp-enables-fleet-management-on-smartphones-tablets/

  I had worked in PHP before, but this was a new effort combining PHP with HTML5 and AJAX.  Development for individual devices such as the iPhone, iPAD, and Android and trying to keep the interface the same across all platforms has been a challenge.  Using the web-app approach has simplified our development efforts significantly, while allowing us to very quickly deploy across multiple smartphone platforms at virtually the same time.  The one exception was Android, which had some issues with the menu interface for the release of 'Ice cream Sandwich', but these were resolved by upgrading to 'Jellybean'.  This has given our clients in the wireless GPS fleet tracking market instant access to their accounts using their mobile phones - and since we included all 9 languages, we were able to deploy it to all of our customers regardless of region.  This was the kind of 'write once, run anywhere' promise of Java, that never really came to fruition.