Plyometrics can be a complement to other strength training activities (you can use it as a contrast alternative). Plyometric uses loaded, controlled movements coupled with the same movement. Examples include super-setting squats, jump boxes, or clap pushups.
Note that these techniques are advanced but very effective to enhance performance and burn calories. But then you have intermediate level plyometric movements, such as, jump rope, jumping jacks, or low-knee tuck jumps mixed with other techniques.