Firebase lets you build apps fast without managing servers.

Name: Firebase

Date founded: April 2009

Company size: 7 employees

Financing: This year, Firebase raised $5.6 million from Union Square Ventures and Flybridge Capital Partners, bringing its funding total to $7 million

Why we like it: Called the Dropbox of apps, Firebase dramatically simplifies app development (and its founders theorize that it could eventually serve about 95 percent of the applications on the web). Plus, the company boasts some pretty impressive customers, including CBS, BitTorrent, twitch, and Code Academy.