This buildpack is made by Hasibul Kabir. This is a Heroku buildpack for adding Plowshare to your application.
The easiest way to do this is with a multipack, where this is just one of the buildpacks you'll be working with.
$ cat .buildpacks
git://github.com/hasibulkabir/heroku-buildpack-plowshare.git
$ heroku config:add BUILDPACK_URL=git://github.com/ddollar/heroku-buildpack-multi.git
By this you can use plowshare in your application.
heroku config:add BUILDPACK_URL=git://github.com/HasibulKabir/heroku-buildpack-plowshare.git
plowmod --install