Twitter has lots of users. It wants a lot more.

That is, in part, why it is planning a massive overhaul of its mobile apps, designed to make the service more appealing to mainstream users.

You should get a first glimpse of Twitter’s new look in the not-too-distant future. Sources say the company is waiting until some time after Apple releases its iOS 7 software update, scheduled for this Wednesday, to show off its new design. It will be Twitter’s third major interface change in the company’s seven-year history.