For Windows there exists TortoiseGIT, sorta fork of TortoiseSVN. Not sure if anything similar exists on Linux or if it could even be done the easy way ("right-click in explorer"), due to the multitude of file explorers/desktop environments.
Linux GUIs are rather poor and usually you just use the CLI.
It's only that i miss sane defaults and a common sense of workflow amongst the community. Currently it's this huge toolbox that can do everything in thousand ways, but to be honest, i don't want to be able to "get my copy of the sourcecode to the server" in a gazillion ways, i would very much prefer one way and one simple command. If you start googling for "how do i do X in git" you will find 10 ways to do X and 100 philosphical discussions why you should do X in a specific way and about "what would Jes^H^H^H Linus do?". For example, i'd love to have "git init" ask your name, email, if you'd like to sign with GPG, etc. etc. and then save this in git, so that every git commit will be signed with GPG without giving that stupid option.
The common way a la "Git" would be to introduce bash aliases, i think. But that doesn't work across machines, OSs or even on the same machine in a different shell.