"Online" and "accounting" in the same sentence? I'm out.
Edit: it seems the on-premise version supports apps: There is no app included in any plan. All apps must be purchased separately from the App Store.
It isn't free as in software, as both FSF and OSI requires software compatible with their goals to have no limitations on use.
I think the traditional standalone accounting software will be a thing of the past here after the implementation of the new accounting law.
Also cloud based accounting systems are probably easier to make money on.
on premise is the exception