Unlock Spanish is a free Chrome add-on developed by enders.preliminary that allows users to learn Spanish while watching YouTube videos. This program covers the browser window periodically with an English word and prompts the user to type in the Spanish translation. Once the correct answer is provided, the screen unlocks and the user can continue watching their video.

One of the key features of Unlock Spanish is its flexibility. Users can set their own intervals for when the English words appear on the screen, allowing for a personalized learning experience. Additionally, users can choose which topics to focus on, ensuring that they are learning vocabulary that is relevant to their interests or needs.

With Unlock Spanish, users can learn up to 400 common Spanish words in an engaging and interactive way. By combining language learning with their favorite YouTube videos, users can make the most of their time online and improve their Spanish skills at the same time.