8 Best Apps From Inc.'s Coolest Young Entrepreneurs

Build a mobile website, find your lost phone, pay your friend that $10 you owe him. You can do all that and more with apps created by our 30 Under 30 honorees. --Donna Fenn

Synthetic's signature product, created by now 29-year-old co-founders Lucas Buick and Ryan Dorshorst, is iPhone photo app Hipstamatic. The app allows users to choose from scores of lenses, films, and flashes to tweak photos and give them a vintage look. Hipstamatic boasts over 4 million users. Read more

Geoloqi, co-founded by Amber Case, 26, and Aaron Parecki, 27, manages location-based services for enterprises, app developers, and government services. Apps built with Geoloqi's toolkit don't drastically drain a cell-phone battery. Read more

AppStack, led by 24-year-old founder Steve Espinosa, makes an automated tool that quickly creates mobile websites for small businesses, and then uses Google advertising to drive traffic to them. Read more

Led by by co-founders John Hering (age 28), James Burgess (29), and Kevin Mahaffrey (27), Lookout Mobile Security protects the devices of some 20 million users from malware, spyware, and privacy breaches. The app also allows users to locate their lost or stolen phones. Read more

Led by 28-year-old Aza Raskin, Massive Health is known for the app The Eatery, which lets users snap pictures of their food and share the image with an online community. The community then rates the meal on an 11-point “fit to fat” scale. Users can follow and invite their Facebook friends to participate. Read more

The music streaming mobile app, brainchild of the now 29-year-old co-founder Daniel Ek, allows premium users to wirelessly sync their Spotify playlists to their phones and listen offline. Or they can go online and stream tracks in the Spotify library. Read more

Led by 28-year-old co-founders Jude Gomilla and Immad Akhund, Heyzap is a social gaming platform that works across varying social networks, allowing gamers to share their favorite games with friends, check into games, discover new ones, and earn badges. The app has been downloaded by more than six million people. Read more

Dwolla, a payment network that circumvents interchanges fees for merchants, is a cheap way to send or receive cash online or through your phone. Under 29-year-old founder Ben Milne, the company now processes between $30 and $50 million per month in transactions. Read more