Available now on a range of Android and Apple iOS devices, the app allows users to play the multiple choice valuation game while the show is being aired live or on-demand.
The BBC said that players can use the app to compete against other viewers in the same room and compare rankings from "novice" to "expert" level.
They can also access exclusive additional information on items featured on the programme via a specially-designed interface. This marks the BBC's first ever live, synchronous smartphone app.
Victoria Jaye, the BBC's head of IPTV and TV Online, said: "We wanted our first live and synchronous companion experience to appeal to a mainstream audience and create a real event in the living room for families across the UK - the Antiques Roadshow mobile app does just that.
"It builds on our successful Red Button play-along quizzes which regularly attract millions of viewers a week."
Last month, the BBC said that the Antiques Roadshow play-along game has proved a big success with viewers since it launched as the corporation's first play-along TV Red Button game in September 2011.
After just nine weeks, the game - also involving viewers guessing the valuation of antiques and items on the show - was played by more than 1.5 million unique users. It proved "especially popular with older viewers", as over-55s accounted for 62% of users, despite making up just less than half of the overall viewing audience.
The companion mobile app uses inaudible signals embedded in the soundtrack of the programme, which are picked up by the microphone of a smartphone or tablet.
These are then used to identify the episode and cue the sequence of correct questions and answers, meaning users can still play the game while watching the show via catch-up on BBC iPlayer or home recordings.
"It's the kind of technology that makes the whole experience really simple and feels like magic." Jaye added.
The new app is available to download now for Android from Google Play and for iOS from the Apple App Store. The first app-enabled edition of Antiques Roadshow will be broadcast on January 6.
Watch a video introducing the app below: