Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
DevDojo - Dev tools and resources for building awesome stuff
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.
UXsniff - Track user behavior on your website and improve conversions with UXsniff: the user experience watchdog that looks out for you.
Bubble.io - Building tech is slow and expensive. Bubble is the most powerful no-code platform for creating digital products.
UX Recipe - Checklist to discover your next UX project tools/techniques