If you want something immediately, there are already a number of programs that will allow people to access their personal computers from an iPad. I've used TeamViewer (https://itunes.apple...d357069581?mt=8) with some success, using a stylus and my iPad to work the full version of Accordance on my computer (with all its modules). I am sure there are other programs, perhaps even some Android versions of such apps that would work equally well. Perhaps some other folks will chime in with suggestions.
We have increased our use of iCloud and DropBox for Accordance iOS. Our mobile app also used Easy Install, so users can download any module they need from the internet. I understand that's not what you are suggesting, but it does point up we're already using the cloud to some degree.
As to a full-blown web app, I am personally not yet convinced that's the way to go, for any of my programs. I do have monthly subscription plans to MS Office, Adobe CS6, and Adobe Captivate, but those programs reside on my computer, where I like them. They are not dependent upon an internet connection to work, just to periodically renew my subscriptions.
I remember when people just had dumb terminals at their desks, tied to some central server, which stored all their files and programs. I also remember the hassles when the central server went down or the traffic slowed everything to a crawl. I loved the move to personal computers, with everything stored locally. Ig uess I am just an independent sort of guy. That's why I am personally in a "wait and see" mode for these new web apps.
Now, that's just my personal opinion, not our company's, but I know of no current plans to develop any sort of web app.
If you want a really inexpensive computing solution, have you considered a "hackintosh"? ;-)