PooleApp – A free, hosted data store for your static sites (pooleapp.com)

The website needs a bit of a proof-reading.

http://pooleapp.com/about/#price "All data remains yours. You can always downlaod all of the data from your forms"

An example usage of this service is baking comments directly into your static sites via a build tool like Gulp or Grunt.

Explained in more details here: http://hawksworx.com/blog/adding-a-static-comments-system-to...