Kettlebell flips are great to develop explosive strength and grip strength. Russian Judokas and Sambo practitioners utilized this method for many years. You will need explosive hips to get the kettlebell enough air time to make the flip. When the kettlebell is coming down it will have a higher momentum in relative to a swing, assuming you are using the same weight kettlebell for both exercises, and you will have to grip and contract your muscles fast and strong enough to make sure the kettlebell does not hit the ground. This exercise will improve your hand and eye coordination as well.
Please note that this is a very elite exercise and should not be practiced until exercises such as kettlebell swings, snatches, cleans are perfected. Another thing to keep in mind is to use a very light weight in the beginning. Since the kettlebell will be coming down fast with momentum, even the light kettlebells can feel quite heavy. The weight should slowly be increased with time. If the weight is increased too fast, you can easily injure yourself. If the progression is not done correctly, this exercise is perfect way to injure your shoulder or elbow so please use with caution.
Check out of Martin Rooney and Jim Miller Rocking rockin out with kettlebell flips.