Online storage firm, Dropbox, announced it’s acquistion of Orchestra, the company behind the Mailbox app for an undisclosed sum.

The move is said to help Dropbox expand its reach beyond file sharing and storage.

Orchestra, which had previously raised over $5m from Charles River Ventures, CrunchFund Angel and others, launched an email app called Mailbox which organises and manages Gmail on Apple iPhone or iPod Touch devices.

The app became highly popular and was made available last month on a first-come, first served basis.

Dropbox said in a blog: "Like many of you, when we discovered Mailbox we fell in love — it was simple, delightful, and beautifully engineered."

"Many have promised to help us with our overflowing inboxes, but the Mailbox team actually delivered."

Over 100 million people use Dropbox to store digital photos, documents, or videos in the Internet ‘cloud’, which can be accessed online from any computers, according to Mailbox.

"They’ve got a ton of experience scaling services and are experts at handling people’s data with care," Mailbox said.

"We’re all looking forward to making Mailbox even better and getting it into as many people’s hands as possible."