Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
Payable - Easily manage and pay your contractors
BuildFire - BuildFire is the easiest way for small businesses to build a mobile app in a matter of minutes for iOS and Android.
Sheet 2 Site - Generate a website from 📗 Google Sheets
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.
Kanda - Affirm for general contractors