Por si algún profe quiere investigar sobre estas 70 apps y ver si le son de utlidad. Yo uso algunas // The 70 Best Apps For Teachers And Students - Edudemic. These are listed as itunes apps, but I'm sure a lot of them can be found for Android as well.
An English Skills poster which demonstrates figures of speech on one side and common grammar mistakes on the other side. Would be useful displayed in a classroom for students to refer to during writing activities.