Instapaper creator Marco Arment has sold a majority stake of the service to the New York-based Betaworks, Arment announced on his blog today.
Instapaper is a bookmarking tool that lets users save content for later reading. Arment said the service was getting too big for him to manage on his own.
"I did almost everything myself, which worked well for the first few years, but for the past year, I've had a lot of trouble keeping up with it," he wrote. "Instapaper is much bigger today than I could have predicted in 2008, and it has simply grown far beyond what one person can do."
Instead of expanding, Arment has decided that he's going to "try other apps and creative projects," so he's handing the reins over to Betaworks. The startup launcher will take over the app's operations and expand the staff, with Arment staying on as an advisor.
Betaworks recently bought social-news site Digg with an aim to bring the site back to its former glory.