This is a personal collection of useful git commands and tools
Install kdiff3 with
sudo apt-get install kdiff3-qt
and then get commit head with
git log
and now you can run for example
git difftool 4fb7737350cc0b646177cb0a041fc73422ffc98a main.c
DeepGit could be an interesting tool: https://www.syntevo.com/deepgit/