This is my position as well. Unless your app is going to provide substantial features over your website or operating system like functionality. I'm not even going to try it out.
I'm a pretty heavy user of it, and it was a godsend to have a nice official Android client that works well. Make use of the web lots on the desktop but it's probably 50/50 desktop/mobile. Love them both .
The only two things workflowy is missing is (1) being able to embed pictures and (2) being able to hyperlink to other nodes to make it act like a graph. It'd be the absolute perfect tool if it had that.
Embedding pictures sounds like a nice idea, but I can't imagine how they could do it and have it look good. If I were them, I probably wouldn't add images.
I kind of hope they resist the urge to keep adding features to Workflowy. It feels done to me and I like simple, focused tools.