Mystery eyes: someone in our class
Here's an idea that might be fun if you have a class blog: every week, we publish a photo of the eyes of someone in the class, and we then attempt to guess who our "mystery eyes" belong to.
By a "class blog", I mean one on which your learners author and publish the content and, besides class projects [example], and what you might publish as being of interest to your students [example], having a different pair responsible for the blog each week will get the students interested and involved. You could have such things as a "YouTube video of the week" or "Album of the week", which the students would be responsible for picking — and "Mystery eyes of the week" would also be fun.
You want the students to take the photos and edit them and want to ensure that other students do comment on the blog, something they could be doing before class, during class, or at home…
An important issue is privacy, so do make sure you have appropriate school/parental permission before you start publishing photos, especially if you are doing this with young learners!
See also: How to make your learners authors