Bonus track: We teamed up with @TIDAL to give new and existing Essential Phone customers a free 3-month TIDAL HiFi subscription. Learn how to redeem this offer and start listening to thousands of MQA tracks today: https://t.co/JUYZD89dto pic.twitter.com/ETM58Hjqa9 — Essential (@essential) June 7, 2018

Essential, launched by Android founder Andy Rubin, is also offering a free three-month Tidal HiFi subscription to all Essential phone owners, so that they'll have something to play using the audio adapter. Tidal HiFi has over 50,000 tracks encoded with MQA, which "allows subscribers to hear music just as it was recorded in the studio; an audio experience as the artist intended," as Tidal describes it.

Essential's PH-1 was marketed from the get-go as a modular smartphone, so the unveiling of a second module is obviously a big deal. The Audio Adapter HD is set to arrive sometime this summer, but the price has yet to be announced. Essential's first accessory, a 360-degree camera, retails for $200, but can be found on Amazon for $76 at the moment. The phone itself, the first with a camera notch (yes, ahead of the iPhone X), has dropped in price from $700 to $499.