Even after Reading Rainbow ended its 26-year-long run in 2009, series host LeVar Burton wasnt ready to drop its mission of promoting reading habits and literacy. He brought the series back as an iPad app two years ago, to much acclaim, but Burton still hasnt been satisfied with what its been able to accomplish. 97 percent of the families in [the United States] have access to the web, Burton tells The Verge by phone. But tablets — where Reading Rainbow now lives — are far more limited: Only about 33 percent have access to tablet computing.