Groll is a project mainly written in Scala, it's free.
Git roller
Roll the git history back and forth from the sbt session and much more.
Contributions via GitHub pull requests are gladly accepted from their original author. Along with any pull requests, please state that the contribution is your original work and that you license the work to the groll project under the project's open source license.
This code is open source software licensed under the Apache 2.0 License_. Just use it, if you like it.
.. _Apache 2.0 License: http://www.apache.org/licenses/LICENSE-2.0.html