Digits, Twitter's password-replacement tool, has come to developers' rescue to solve one of the biggest problems for Apple TV—how do you log into apps and services when all you have is a remote control? 

Digits for tvOS, Apple's operating system for TV apps, lets developers authenticate users without entering a phone number or confirmation code into the TV itself. Instead, the Apple TV displays a code to the user that they can enter on the Digits website.

It's a good example of Digits' push beyond its initial service, which was based solely on phone-number logins. At this year's Twitter Flight conference for developers, Twitter revealed an expansion of Digits to handle email logins as well as phone numbers. Neither of those options, though, worked well as on-screen logins for Apple TV—hence the off-screen login code. 

This method is popular with other TV apps, like HBOgo, Showtime Anytime, CBS All Access, and others—so Twitter is now making it easy for smaller developers to match a popular TV-app login method.

Many mobile developers who use Twitter's Fabric services will be familiar with Digits,  as the tool is already a means to replace passwords with a user's mobile phone number. Upon entering their mobile phone number, the user receives a confirmation code via text message from Twitter which is entered in place of the traditional email address and password. (Twitter foots the bill for these text messages, which is an additional draw for Digits.)

The text-message login worked well for many mobile users, particularly in developing countries where smartphones far outsell computers and many people may not have email addresses. But it proved a barrier to Digits' adoption by developers in Western countries, where email logins are more established and email marketing to existing users is seen as a key way of ensuring growth and retention.

Twitter isn't the only one courting Apple TV developers. Facebook announced its SDK for tvOS beta in November, including Facebook login for tvOS apps. But Facebook's Parse framework for mobile-app developers is still testing tvOS compatibility, with an experimental branch available on GitHub but no official support.

Digits is only one part of the software-development kits that make up the Twitter mobile development platform,Fabric . The Crashlytics kithas now expanded to include tvOS, enabling developers of TV apps to analyze and fix crashes quickly. 

It's not yet clear how Twitter plans to make money off of Fabric, which it doesn't charge for, though the company has said it anticipates Fabric developers will tap into Twitter's advertising services, too, boosting the company's overall revenues. To that end, it makes sense for Twitter to want Digits and other parts of Fabric to run on as many platforms as possible.

Lead photo by Owen Thomas for ReadWrite; screenshot courtesy of Twitter