I usually do 'git checkout <branch/tag/sha_of_commit> -- <filename>' to revert a single file to previous state. If I ever need a gui (very, very rare), I would

I usually do 'git checkout <branch/tag/sha_of_commit> -- <filename>' to revert a single file to previous state. If I ever need a gui (very, very rare), I would just use 'gitk'. Small and does the work.