New Delhi, May 16 : Twitter is working on a paid subscription model and now, app researcher Jane Manchun Wong has found the service will be called Twitter Blue, costing $2.99 (over Rs 200) per month. "Twitter Blue" will include an 'Undo Tweets' feature and bookmark collections. "Twitter is calling their upcoming Subscription Service "Twitter Blue", priced at $2.99/month for now, including paid features," she said in a tweet on Saturday. According to her, it appears that Twitter is working on a tiered subscription model, which means a less-cluttered, premium experience for the subscribers. "Twitter is working on Bookmark Collections, aka the 'folders in bookmark' that lots of folks have asked for," Wong said. Twitter was yet to react officially on the tweet. Earlier this month, Twitter acquired Scroll, the $5-per-month subscription service that removes ads from websites that participate. Twitter had hinted that it was planning a paid subscription platform that can be reused by other teams in the future. Twitter aims to more than double its total annual revenue to over $7.5 billion in 2023 with at least 315 million mDAU (monetisable daily active users), according to its CEO Jack Dorsey. "Our goal is to more than double our total annual revenue to over $7.5 billion in 2023. This requires us to gain market share with performance ads, grow brand advertising, and expand our products to small and medium sized businesses throughout the world," the Twitter CEO had said. /IANS