Baqend Platform - Baqend is a Backend-as-a-Service for web and mobile apps.
Parse - Build applications faster with object and file storage, user authentication, push notifications, dashboard and more out of the box.
Backendless - Backendless is a mobile Backend as a Service (mBaaS) platform.
AWS Amplify - JavaScript library for app development using cloud services
Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.
AWS Mobile Services - Storage, Analytics, Push Notif. & SMS Delivery SDKs