Because of the nature of the new app model for SharePoint Hosted apps which gives us no access to server logic, how can you possibly setup File Uploading for older browsers like IE8 that don't natively support file uploads on the client?
Typically you got around this by posting to some server logic, but there's no ability to do that in 2013 without running into access issues (due to cross domain).
Ultimately, if you could post to the _layouts/15 directory this would be a non issue, but we get forbidden errors attempting to due so because of the app/host security model.
Does anyone have any idea how you could accomplish this? Please note we can get this working no issue for IE 9 and higher, Firefox and Chrome because they support html file upload.