When I stand with my feet flat and together, then lift myself onto my toes repeatedly. It's a pretty good calf workout, and I do about three reps of 100. Is there a name for this exercise/movement?
Those are Calf Raises. Calf raises are used to strengthen the lower legs. Calf raises may sometimes help with shin splints depending on the location of the pain.
Toe raises are the opposite lift and should be done in conjunction to avoid muscle imbalances. Stand flat footed and lift your toes towards your shin bone.