Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
JSON Generator - Create mock and sample JSON using a powerful template syntax
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.
Mockaroo - A realistic data generator to test your app
Bubble.io - Building tech is slow and expensive. Bubble is the most powerful no-code platform for creating digital products.
Ideas Are Worthless - Like Product Hunt. But for Ideas.