In short: Some good videos. The material for lower-level students covers things like prepositions, address vocabulary, etc. Joan, the site’s author, does a wonderful job of going slowly and including nice images in her videos. It’s nice to find videos that really low-level students can use. Intermediate and advanced students will find nice stuff too, but will probably prefer a site that goes a little faster.
Also, for just $10 a month you gain access to a lot more videos, quizzes, etc. She also offers private lessons at the incredibly low price of just $30 per hour.
For students: Check out this mystery. You can ask her questions or read the comments to learn more.
For teachers: Send your beginner students to watch these videos as review for what you’ve covered in class.