Adobe's EchoSign, the company's online digital signature service, is now available as a free iOS app.

The app will allow users to add legally-binding signatures electronically to documents on the iPad, iPhone and iPod touch and then send them on securely to their intended recipients.

The app is an extension of Adobe's EchoSign online service, which is used by four million people worldwide, according to the company. Adobe acquired the technology when it bought EchoSign in July this year.

"The enterprise is experiencing unprecedented adoption of tablets and mobile devices, presenting new opportunities to leverage cloud applications to streamline business processes and greater efficiency," said Jason Lemkin, vice president of Web business services at Adobe and the former CEO of EchoSign.

"With the Adobe EchoSign app, we’re making it that much easier for organisations to incorporate Web contracting into their business models, allowing users to sign documents and send documents for signing right from their iOS device. The end result is a higher rate of contract completion in less time, leading to increased productivity."

The app can be downloaded for free from the App Store. You can sign up to create a free EchoSign account on the service's website.