You can also use the mobile app to view data you can't see on the full site - like feedback information on accounts that have been deleted.
If you go into old emails on the app and find a user account that is now dead, it will say it can't be displayed because the user is no longer active. But click on the feedback number next to the name and it will display all the original feedback comments that can't be accessed on the main site. It even works if they have 0 feedback but people have left information only comments. Could be useful if you ever need to check up old user accounts.
A bit like the issue with Rochdull Lad's old user name still being active, I think it's because the app gets data from a separate mobile server on a different address to the main site which should be an exact mirror, but sometimes isn't. Mobile Facebook used to be the same - comments you had hidden or deleted on the PC version could still be seen on a mobile phone - but I think they might have corrected that now.