Yes! With Mango Languages, you are able to skip lessons and begin at any lesson or chapter of your choice.
Whether it be in a browser or in the mobile app, simply launch your course and select the Unit, Chapter, and Lesson where you would like to begin. For example, in the below screen shot, this user has not studied lessons 5, 6, or 7, but he has decided to skip ahead and study lesson 8.
When watching a Mango Premiere movie in Engage Mode, click Chapter / Scene near the top of the screen to view the available scenes. This is where you can go through each lesson or scene and select where you would like to begin.