I recently did a task on swagbucks that was crowdflower powered, but it's pay was awful on swagbucks. I don't know if they're on another cloud platform or not.
Crowdflower is in their own website and other PTC sites where they paid even less than they did in Mturk. Oscar Smith got ****ed over by another company so he is pretty much gone.
Crowdflower pays good relative to the typical PTC. Now, they're still $2/hour, but it's better than $1/hour.