The documentation is lagging or is out of date.
This is especially true for low cost or free apps. There's no money or time to put into the documentation and it may lag, or rather take time to get that fixed.
Some clients or users will consider this a bad thing while others use the app but never read the documentation so why create or maintain documentation that only a few will read?
You have your reasons to switch but if the app works, that could be good enough for many.
Hi all
I am really upset about this tool.
I find quite a lot of discrepancies between the present interface and contents and the procedure manual of Nozbe.
Nozbe never changed the contents of procedure manual for a long while. I am afraid Nozbe has been doing it intentionally.
That means they persuade a user to pay.
If this one is true, very terrible.
For example, the below is the reply from Nozbe
https://gyazo.com/49b6a74d4e2472558565a3cfbb223165
When are the contents of help page?
No point if the contents of help page had changed then.
Under the said circumstances, I would like to discard Nozbe.
I am now thinking tool without Asana, Toodledo.
The important thing is no discrepancies between the present interface and contents and the procedure manual of my desired tool.I would not ask the help center often.
My purpose is that I intend to use my personal to-do management. As group GTD, I will use Trello.
Looking forward to having your advice.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic