Being able to export to csv directly to file on your phone. Not via email... or allow for encrypted zip.
As far as I can see the only possibility to export csv data is to have it sent, unencrypted via mail. This may be necessary for a more advanced pdf generation but to just export the raw data as csv should be doable by the app directly to storage on the phone. The db query and packaging to a .csv seems pretty straight forward.
Since I can view the data in the progress/list view and browse it even if I am in Airplane mode the raw data must already be in the phone.
This feature would mean that I can then care for the security of the file myself and protect it the way I want if I need to move it further.
As an alternative have the possibility to in the app specify a password and have the servers use the built in crypto in zip so that there is some protection of the data sent via mail.