Akinator

Akinator looks like the perfect pastime for all-level students to relax while keeping in touch with their English. Lower-level students can even consolidate Yes-no questions by paying careful attention to all the questions the genius keeping asking you. You will also have the opportunity to revise lots of job-related vocabulary.

Self-study idea:
Get together with an English speaking friend or relative and play Akinator two or three times to learn the mechanics of the game. Then you play Akinator yourselves. Think about a famous person, or celebrity, or sports personality, or politician and get your friend to find out the person you have in mind by just asking yes-no questions. This the famous Twenty Questions game we have often done in the classroom.

H/T to DDeubel.