I have found a variety of visual discrimination apps that have proved useful. I mostly use these apps as a supplement to another main therapy goal or activity. If I am working on comparing and contrasting, I may have the student do several activities, whether it is through therapy cards, venn diagrams, or another "tell me how they are the same and different" type of task. As motivational reinforcement, I use any of the following apps. The students can compete on an individual level, with a partner, or with the therapist. When playing with a partner, we simply pass the iPad 2 between students/therapist and take turns finding differences. Part of the turn also includes making eye contact and whole body listening. It is great for other social skills, such as: shared interest and attending/staying with the group. The students must watch during their partner's turns as well...they can not leave the group or have their body turned away from the partner.
The goal is to compare two pictures and identify subtle differences. These are great apps for students who may have difficulty focusing, scanning the entire screen, etc.
Find the Differences: Pirates (My First Games) - So far, I only have the 'lite' version, which has 2 scenes open. You can also select difficulty level: 1 star (easy) 2 stars (medium) 3 stars (difficult) for each scene. There is cute background music and the graphics are decent. I like it!
Find the Differences HD - This is the same as the Pirates game; however it has animal themes. Again, I like it!
These were my favorite so far. Other apps included Differences and Find Photo Differences; however, the pictures were more difficult and not of as good quality. Most of my students did not prefer these and were not as successful.