Here are some tips on using Sandisk Wireless Flash Drive:
You can use cards with more capacity than 32GB if you format them in FAT32 (see http://kb.sandisk.com/app/answers/detail/a_id/8075 ). You are still limited to filesize of 4GB though. Sandisk promised support to ExFAT on a future firmware release, which will enable files bigger than 4GB;
You can use the AirStash+ App to access the drive on iOS, which is better than the Sandisk app, allowing you to open files with other apps;
You can access the files through WebDAV protocol. The address of the device can be obtained with the AirStash+ App mentioned above;
My primary way to access my files is through WebDAV with the FileBrowser app ( http://www.stratospherix.com/products/filebrowser/ ).
Hope this helps.