One third party app that didn't get a lot of love (apparently) is/ was Microsoft Cache - an "Evernote-Keep" competitor launched as a Garage project last year. It may be evidence of the difficulty of creating a competitive product in this market that Cache is being closed down...
http://www.cio.com/article/3159672/windows/microsoft-kills-cache-its-note-taking-experiment-with-evernote-google-keep-aspirations.html
"When Microsoft launched its Cache note-taking experiment last year, we hoped it could become Microsoft’s version of Google Keep, if Microsoft devoted enough resources to it.