checknlearn is a free Chrome extension developed by Tomasz Nieżurawski. It falls under the category of Browsers and is specifically classified as an Add-ons & Tools subcategory.

This extension offers a convenient way to look up word definitions while reading online. By simply double-clicking on a word, users can instantly view its definition without the need to open a separate dictionary.

However, checknlearn goes beyond just providing definitions. It also offers a unique learning feature. Users can create an account on checknlearn.com and receive push notifications to their smartphones about the words they have checked using the extension. This serves as a helpful reminder to practice and repeat the vocabulary they have encountered.

With checknlearn, expanding your vocabulary becomes easier and more efficient. Say goodbye to flipping through dictionaries and hello to a seamless learning experience right at your fingertips.