Steam Desktop Authenticator
SDA, (Steam Desktop Authenticator), is a creation of Jessecar96. It is a desktop implementation of Steam's mobile authenticator app. It allows you to get Steam Guard codes on your computer, which is great if you don't own a phone, or do not wish to use your phone for this purpose.
My implication of SDA changed the UI to look a bit nicer in terms of design and layout. My version of SDA also includes some changes like a theme editor, the abilty to download and apply updates via the program, and other minor bug fixes. My spinoff of Jessecar96's version is usually up-to-date with theirs, but may have a 2-3 day delay. If you found an issue with SDA, you can either leave a bug report, or message me personally on Steam.
View the full project page here.