In the PC version if a file is posted you can click on it and open it externally.
This allows the user to print, email, download, whatever they need.
In the mobile version when you tap a file it is only displayed within the app.
This means that the functions you actually want to do cannot be done in the app.
As a student who's printer only connects to her phone, this is annoying.
Please allow files to be externally opened from the app.