The Glass app -- or "Glassware" in Google parlance -- projects GTA3's GPS system onto Glass's screen, which is placed in front of a user's right eye. The hack allows players to better navigate Liberty City, GTA3's fictionalized version of New York City, Mr. DiGiovanni said. Rather than having to constantly switch their gaze from the GPS map in the corner of the screen to the game's character in the center of the screen, gamers get a constant view of both.
He wants to call the app Glass Theft Auto, but he's worried that people will wrongly think its an app that helps users steal cars -- in real life. He's instead opted for GTA Navigation for Glass, an admittedly more boring name, he said.
Mr. DiGiovanni came up with the idea while playing "Grand Theft Auto V," or GTA5, the latest version of the wildly successful Rockstar Games franchise. Playing the game on an 80-inch projection screen made it difficult for him to simultaneously monitor the game's characters and the GPS map. As an avid Glass user and developer, he sought to create a Glassware solution.
When Mr. DiGiovanni couldn't find a way to access GTA5's data through his PlayStation 3, he tried to create the same solution for "Grand Theft Auto IV." He had trouble loading GTA4 onto his various computers, though, so he ended up creating the app for GTA3.
GTA Navigation for Glass is Mr. DiGiovanni's fourth piece of Glassware. The others include Launchy, an app for housing Glass apps; Winky, an app that allows you to take a photo with the bat of an eyelash; and Bulletproof, an app that solves Glass's data security problem.
He has not developed any Glassware for clients, but he thinks the device could change how many companies conduct business operations.
"We are just kind of approaching it as 'How can we build up our knowledge base?'" Mr. DiGiovanni said. "If Glass doesn't catch on with consumers, there's still a ton of ways companies can use the devices internally."
He believes that Glass could be particularly transformational for gaming.
"The app might open the conversation of Glass and wearables as second screens of gaming," he said. "It could open a whole new genre of games that we've never really seen before."