That’s one of the program’s common usages, yeah. Among other things (like integer scaling for pixel-based games), it can be used to:

• render a game at a lower “internal” resolution and then apply one of several upscaling options to make up the difference, improving performance and hence “free FPS”, and/or
• generate intermediate frames between “real” frames, which I guess you could describe as “free FPS” (but the quality of the intermediate frames will be so-so - there’s lots of tests and stuff of frame generation more broadly if you’re interested!)

edit: added frame generation