Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.
Zoho Creator - Zoho Creator is a low-code application development platform that helps you build a custom, mobile-ready apps to run your business.
restdb.io - restdb.io lets you create databases and REST APIs quickly. Development databases are free. Powerful web-based and mobile-friendly data management.
QuickBase - Quickbase provides a no-code operational agility platform that enables organizations to improve operations through real time insights and automation across complex processes and disparate systems.
RemoteStorage - An open protocol for per-user storage OWN YOUR DATA