Google Vision AI - Cloud Vision API provides a comprehensive set of capabilities including object detection, ocr, explicit content, face, logo, and landmark detection.
Flico - Add visual search to your Chrome browser
Amazon Rekognition - Add Amazon's advanced image analysis to your applications.
Imagga - Advanced image recognition technology wrapped in powerful API.
CaptionBot by Microsoft - Analyzing and describing images by a bot
Clarifai - The World's AI