At Japan Amusement Expo (JAEPO) 2019, Konami revealed that they are working on mobile games for the BEMANI series, including beatmania IIDX, Sound Voltex, and DanceDanceRevolution. [Thanks, 4Gamer!]
The games are set to be playable just on the phones themselves, but Konami will also be releasing peripherals for the mobile versions. If you use the phone’s screen output capability, you can play the game on a monitor or TV display instead.
The games are set to be smartphone-exclusive, and what tracks will be included have not been revealed. As for how the game will be monetized, that has yet to be revealed as well.
The Ultimate Mobile Series set of games, including beatmania IIDX, Sound Voltex, and DanceDanceRevolution are currently in development.