I've never heard of a creature to eat algae as long as the next best thing is available. Even snails will eat fish food before algae. Besides Nerite snails and Otos there' no other creature that eats algae exclusively.
Be weary of this! SAE become lazy bastards once they grow, Amano shrimp will eat algae as a last resort.
All algae eating creatures prefer dying algae or dead plant matter. Don't be surprised if you don't see any activity or the creatures don't put a visible dent in the algal population.
In my shrimp tank I put a floating magnet that was covered with dried BBA and the shrimps went nuts over it. The live algae is fine otherwise.