hk is a faster Heroku command-line client, which is by Heroku but is unsupported and has to be installed from source. It's written with Go and supports zsh and bash completion.
That means if you've got
hk and vim-heroku, you can get tab completion in Vim as well.
If you're heavily invested in Heroku and general Vim-laziness, then you might also like heroku-remote which helps manage multiple Git remotes for Heroku applications. This is useful if you've got different environments -- I usually have a staging environment, for example.
Heroku binstubs is yet another Heroku script by Tim Pope that helps to avoid having to type
--app app-staging all the time. This is one of those annoyances with Heroku that I've never figured out myself.