If you have ever dived with me or seen me dive, then you know that the majority of the time that I am underwater I use the frog kick. I find the frog kick much easier to use then the flutter kick. I am able to glide more and it exhausts me less than the flutter kick. I encourage all of my students to start using the frog kick as soon as they have gotten their buoyancy and trim under control.
One major benefit of the frog kick is that it stirs up less silt, meaning that you are less likely to destroy the visibility for yourself and other divers. Another is that when you learn to frog kick the natural progression is to learn to helicopter kick and to back fin.
Here is a great introductory video on the frog kick. It wasn’t made by me but it is a great start for those looking to learn more about it.