Twitter has inadvertently confirmed that it is working on a subscription service called "Twitter Blue." The microblogging platform will offer Twitter Blue subscription as an in-app purchase through its app.

Details about Twitter's subscription service first leaked in mid-May.

Twitter Blue to Offer Color Themes, Custom App Icons

Security researcher Jane Manchun Wong first discovered that Twitter updated its App Store listing with Twitter Blue as an IAP option. The listing also confirms that Twitter Blue will cost $2.99 per month. For further testing, Wong went ahead and subscribed to Twitter Blue, possibly becoming the first customer of Twitter's subscription service.

As a part of the subscription, Twitter will allow users to change the color accents in the app. Subscribers will also have the option of using a custom app icon for the Twitter app.

Other features that will be a part of Twitter Blue have been leaked previously, including the ability to undo a tweet. This feature won't retract a tweet that's already live but delay posting it by a few seconds. Subscribers will have the option to customize the undo tweet timer from anywhere between 5-30 seconds.

Twitter Blue will also feature Collections to save and organize your favorite tweets into folders. Reader Mode will also soon be a part of Twitter Blue, which will make it easier to read long Twitter threads. Sadly, Twitter is seemingly not planning to reduce or do away with ads on the timeline and its app for Twitter Blue subscribers, at least initially.

Related: Twitter Hashtags That Shaped History

Since Twitter plans to offer Twitter Blue as an in-app purchase option through its iPhone app, it will be paying Apple a 30 percent fee for every transaction.

Twitter is rumored to include Scroll as a part of the Twitter Blue subscription, which it acquired in early May. Scroll is a subscription-based service that offers an ad-free reading experience from publications that are a part of its program. It claims to offer publishers up to 40 percent more revenue than ads.

Twitter Blue Could Launch Soon

Twitter updating its iOS App Store listing with Twitter Blue details points to the impending launch of its subscription service. What remains to be seen is if the company will add more features to Twitter Blue before making it live to make it more enticing for its users.

Given the current set of features that have leaked, Twitter Blue might just be a hard sell for $2.99/month.