Yes its Filger, looks like the Shestak UI author has changed it, his contains Filger.lua and Settings.lua and afaik everything is usually done with just Filger.lua also looks like his changed it to use spell ids. Apart from the preceding stuff the fact that some of it is in Russian probably didnt help matters when you tried to use the addon in your own UI. If you look through here you're bound to find some UIs with Filger set up, 95% certain if you take Filger from here it should work without any form of Tukui. That author has it setup for mages to show certain important raid debuffs and PVP stuff in specific areas of the UI, similar to the Shestak screenshot.
Assuming you know how to mess with lua files (open with something like SciTE or notepad+ for best results) it should be fairly easy to learn how Filger works by looking at what other people have done. Just when u set config mode to true and you first log on to a char all the groups you've set up for that class while be in the center of your screen. Mouse over the square/bar with the group name and hold shift-ctrl-alt and drag the group to where u want it.
If you're looking for similar addons both sfilter and rfilter are configured with lua too. While Auracle and SBF have beefier in game options and prob more features, Auracle certainly does and SBF can track every frame (apart from raid ones I think) be careful not to creat too many groups and filters with SBF or u might run into performance issues.