Microsoft Office Access - Access is now much more than a way to create desktop databases. It’s an easy-to-use tool for quickly creating browser-based database applications.
Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
MongoDB - MongoDB (from "humongous") is a scalable, high-performance NoSQL database.
BuildFire - BuildFire is the easiest way for small businesses to build a mobile app in a matter of minutes for iOS and Android.
My Visual Database - Using My Visual Database, you can create databases for invoicing, inventory, CRM, or any specific purpose.
MIT App Inventor - App Inventor is a cloud-based tool, which means you can create apps for phones or tablets right in your web browser.