The FT report claims that a beta version of the app is being tested by a selection of Android smartphone users and that it bears a greater resemblance than its existing app to the apps of rivals such as Facebook.
For Twitter, mobile is core to its earning ability, so refining its app to make it more appealing to attract new and retain existing users is crucial.
According to research firm eMarketer, Twitter is expected to earn $582m in global ad revenue this year, rising to around $1bn in 2014. Mobile is thought to account for more than half its revenues.
Twitter announced last week that it had filed documents with US financial regulators as it prepares to float on the stock market. The firm revealed the news via a tweet from its official account, stating: "We’ve confidentially submitted an S1 to the SEC for a planned IPO. This Tweet does not constitute an offer of any securities for sale."
Earlier this month, Twitter announced a commercial deal with Cadbury-owner Mondelez, that would see Twitter teams embedded at Mondelez’s global offices, including in the UK, US, India and Brazil.