Here are a couple of apps gone free (on 12/13/2014) that might support visual perceptual intervention for younger students:
Shapes Memory Match (iPhone/iPad, originally 3.99) is currently free. The app provides preschool activities of shape identification and recognition in a memory matching activity.
Sharing with Duckie Deck app (iPhone/iPad, originally 2.99) promotes sharing with visual matching and memory activities for 2-5 year olds.
Just a reminder – apps gone free are typically only for a mysterious period of time!
Free apps to consider for your mobile tool kit!