Two other nice apps in this space are Workflowy[1] and Dynalist[2].
[2]: https://dynalist.io
[2]: https://dynalist.io
I'm also interested in self hosted apps.
I have a self-hosted solution. It's in an alpha state, not ready for public consumption, but would love any feedback from people willing to try it out. Here it is:
https://github.com/ryanfmurphy/db_viewer
This started as a DB Admin tool ala PhpMyAdmin, but I now use it for Todo lists, tree-style mind-mapping / brainstorming, tracking finances, etc.
If you give this a shot feel free to email me for help setting it up / getting the most out of it. (Email is in my profile)