Playment is described as 'On-demand workforce for image annotation and content moderation'. There are eight alternatives to Playment, not only websites but also apps for a variety of platforms, including iPhone, iPad, Ruby and Python. The best alternative is Amazon Mechanical Turk. It's not free, so if you're looking for a free alternative, you could try Spare5. Other great sites and apps similar to Playment are Appen (Paid), Sequence.work (Paid), Scale (Paid) and CloudFactory (Paid).
ImageAnnotation.Ai provides image tagging and annotation services for deep learning, machine learning and computer vision companies. To make sure they're a good fit for your project, you can start on a small batch of your image or videos for free. No hassle and no commitment.
The fastest, smartest and collaborative way of image annotation for Machine learning and AI. OCLAVI is an annotation tool which helps in making models learn precisely and work accurately in the real world.