AppConvertly.com - AppConvertly - convert your website to Android & iOS app. No coding required. Easy solution to reach new audience in 5 minutes https://www.appconvertly.com/

Create - CREATE is a powerful and intuitive mobile creativity tool.

calibre - Ebook manager, viewer & converter

Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.

ConstantLink - Within two years of releasing your e-book, your external links will stop working.ConstantLink redirects your readers to working sites, so you can focus on writing.

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.