The backstory has been blogged here
Just me. That is the great thing about the Free Open Source Software (FOSS) community, one person can take existing projects and build on top of them.
Most of the work has been the scripts and configuration files that work in the background keeping everything working. This includes resizing the panel, selecting an appropriate size wallpaper, managing the browser toggle, the lock dialog, the lockscreen sentry and more.
Furthermore, I created a few webapps: a calculator, a stopwatch, a countdown timer, and a wage counter for this project. The timer, email and wageclock icons I made from scratch in GIMP; the notes, calculator and shutdown icon are modifications on existing icons and the rest are from Gnome, Hicolor and Tango icon sets.
I hand-picked the bookmarks, extensions and adjusted settings for both browsers to ensure a comfortable and quality experience. Lastly, much of the time has been spent fixing bugs (many of which were caused by SystemD).
You can close pop-ups with ESC and other windows with ALT+F4 or CTRL+Q
The boot menu displays the build date in YYYYMMDD format: