This is a Heroku buildpack for adding unzip to your application.
More likely, you'll want to use it as part of a larger project, which needs to use unzip. 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/heroku/heroku-buildpack-ruby.git
git://github.com/niteoweb/heroku-buildpack-unzip.git
$ heroku config:add BUILDPACK_URL=git://github.com/ddollar/heroku-buildpack-multi.git
This will bundle unzip into your instance without impacting your existing system.
$ git clone http://github.com/niteoweb/heroku-buildpack-unzip.git
$ cd heroku-buildpack-unzip
$ heroku create -s cedar
...
$ heroku plugins:install https://github.com/heroku/heroku-repo.git
$ heroku plugins:install https://github.com/glenngillen/heroku-exit-status.git
$ heroku config:add BUILDPACK_URL=http://github.com/kr/heroku-buildpack-inline.git
...
$ git push heroku master
...
$ heroku run "unzip -v"
UnZip 6.00 of 20 April 2009, by Info-ZIP. Maintained by C. Spieler.
...