Movies, for instance, run at 24 frames per second, which means each frame is .04166666667 seconds long. You can round up those numbers in many ways, like .04167 or 0.417 or 0.42, making things hard for the people working in visual effects and post-production -- the CGI artists and programmers who need to make sure everything is in sync. The idea behind Flicks is to simplify those numbers to keep everyone in the same page. 24 FPS is 29,400,000 flicks. 60 FPS for video games is 11,760,000 flicks. Much simpler, right? In short, Facebook is trying to set a new standard for industries working with units like FPS and kHz that tend to have decimal points.
Flicks was created by Christopher Horvath, a former Facebook employee part of Oculus' Story Studio, with help from a lot of people. You can find out more about Flicks through its Github documentation, which explains:
"When working creating visual effects for film, television, and other media, it is common to run simulations or other time-integrating processes which subdivide a single frame of time into a fixed, integer number of subdivisions. It is handy to be able to accumulate these subdivisions to create exact 1-frame and 1-second intervals, for a variety of reasons."