Notepad++ - A free source code editor which supports several programming languages running under the MS Windows environment.
Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
Sublime Text - Sublime Text is a sophisticated text editor for code, html and prose - any kind of text file. You'll love the slick user interface and extraordinary features. Fully customizable with macros, and syntax highlighting for most major languages.
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.
PSPad - Text, code and hex editor.
Bubble.io - Building tech is slow and expensive. Bubble is the most powerful no-code platform for creating digital products.