This type of post pops up once a month or so... I'm a Sr. Mobile Developer, built plenty of iOS/Droid apps for my company. I offered to help WIS out in this area a while back (6 months or so), never got a response (sarcastic surprise face goes here).
Assuming they had an API framework built already that I could get access to and documentation for with all the necessary calls, I could fairly quickly knock an app out that'd probably make some of the more tedious uses like recruiting and game planning from your mobile device easier. If I had to write the whole service library back end it'd obviously take longer. I was working on some storyboards and basic flows for an app when I first started looking into it, but given the lack of interest on WIS behalf, it was just a waste of time. I could write something HTML based, but it'd be crazy slow and just a bad experience... you'd be better off dealing with the site. I was working on app back in October or so that would perform mass recruiting actions and had it mostly working through HTML, so I know it's possible given their site structure, but the response time on everything being completed was horrid due to all of the extra logic I had to throw in for every action.