Controversial social-media app Parler has come back online after more than a month without service. The Twitter-like app was a favourite among supporters of former US President Donald Trump and right-wing conservatives. It was banned from Google and Apple's app stores and Amazon's web-hosting service, after an armed mob broke into the US Capitol building on 6 January. But now, the self-styled free-speech platform says it is "here to stay". The app was not available for all users immediately, however. And users reported their posts from the previous version had vanished from their profiles.