StumbleUpon has finally released its mobile apps for the iPhone and Android.

"Think about all those times when your’e riding the bus, sitting at the airport gate, or waiting for friends, playing with the same mobile apps again and again," says StumbleUpon’s mobile apps team. "Now you can have the perfect boredom-buster: with StumbleUpon for the iPhone and Android, the best of the web is, literally, at your fingertips."

"Following the success of our iPad app, we’re excited to extend the stumbling experience to iPhone and Android device users, letting people explore the best of the web at any time no matter where they are," said Garrett Camp, founder and CEO. "Downloading the app is easy and once logged-in, users can discover great online content that’s tailored to their preferences."

Users can thumb-up or thumb-down sites from the phone, just like from the desktop. You can also narrow down the "stumbling" to a particular category or site such as or YouTube.

You can also use the app to share content with other users through Facebook, Twitter, or email.