Sorry about the name
The latest version of Grenchman is 0.2.0, but it claims to be 0.1.0 on account of releases being hard. Distributed native binaries are about 10MB but have no dependencies required besides libffi and libreadline-dev. All programs are 64-bit.
Download the appropriate binary for your platform, set the executable bit with chmod, and place it on your $PATH as grench to install. You can check the signatures by pulling in the key with gpg --recv-keys 77E77DDC and running gpg --verify $ASC_FILE.