Almost got ultra angry at ArtStudio for iPad

I was trying to backup all my drawing on my iPad by exporting everything to psd, since this is the format that preserves all the layers.  I use 2 drawing application on iPad: SketchBook Pro and ArtStudio.  SketchBook has no problem exporting files into psd, and I can directly get the exported files through iTune.  The PSD export experience of ArtStudio was, on the other hand, pretty disappointed.  I have to export and send the PSD file to my email account.  But the worst part was that the email process kept crashing the application.  Eventually I had to reboot the iPad and from then on the export to email was pretty OK.  Still, I think I am much perfer the user interface of SketchBook Pro.