Both the dog and cat versions of Revolution have the same active ingredient, selamectin. However, the strength (concentration) is double in the dog doses; moreover, you get more per vial.
http://www.drugs.com/vet/revolution-45-mg-can.html

I use the Revolution Plum for X-Large dogs to treat my feline pets and rescues. One vial of the Xlarge dog treats 16 cats if they weigh over 5lbs. That comes out to 4 drops per cat. I squeeze the tube into a clean shot glass and use a dropper. For kittens over 6 weeks, only 2 drops are needed.

It works on fleas, ticks, ear mites, mange, and many worms, including heartworm. It is also long-lasting: typically treatment is needed every two months. It also seems well tolerated and doesn't lose effectiveness (like Advantage seems to do after a while).