I have made a Google Drive app and I now have trouble getting my app to be shown for the "Open with" menu.
In the Google Apps Developer console I have registered "text/csv" as the primary mimetype and checked "Allow users to open files that can be converted to a format that this app can open.".
I have tried, as a test, to add the mimetype "text/plain". Then I can access Google Docs files fine in my app.
My questions is, what mime type should I register to be shown in the context menu for Google Spreadsheet files?