Narangi is an Android app designed with the help of friends at the HomiBhabha Center for Science Education. It lets you draw with your finger in black on orange, and also sense what you have drawn -- when you move your finger on the screen, the device vibrates when there is black color under your finger. To clear screen, change the phone orientation from landscape to portrait or vice versa.
Watch a short video on Narangi.
Do you have any app ideas for people who are deaf-blind? If so, email Dr. Arun Mehta at arun (dot) mehta (at) gmail (dot) com.