Nashville: Without looking down, Kira runs her index finger across the screen of an Android tablet that she is holding in her lap. For the occasion, she has painted her fingernails bright pink. When her finger touches a line drawn on the screen, the tablet vibrates quietly. Scanning her finger back and forth and feeling the vibration come and go allows her to trace the line’s path. When her finger reaches a pink dot, the tablet gives off an electronic tone and she grins delightedly.