Download: http://www.syntevo.com/smartgit/download (7z archive)
Licence: Free for non-comercial use.
Tested: Portable (.settings folder in program directory)
Stealth: No (.oracle_jre_usage in home directory, Local Temp stuff, HKCU\software\ej-technologies, might be more)
Comes with it's own JRE and Git. According to this source, the JRE doesn't interfere with any installed JRE.
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Another interesting program from the same company: DeepGit
Also comes in a portable 7z archive, although I haven't tested it. Quick run has .settings in the program directory. At the moment it's in a testing phase, but according to the site will be released soon.No licensing, no ads, no collection of emails addresses. DeepGit is free to use for everyone, even in a commercial environment.