English Words Finder is an app that helps you easily find definitions for over 60k words.

There are no ads and the app is completely free.

You can organize your words into lists and have them synced on all devices.

English Words Finder is one of the apps from the learning curriculum at the Full Stack JS course => js.coderslang.com
If you want to become a mobile or web developer, it's a great place to start. Even from scratch!