I downloaded the Sennheiser CapTune app from Google Play as I wanted to try higher quality audio and in the options was a 3 month TIDAL trial on the HiFi subscription. After the free trial, the price is £19.99 per month. Sign up (payment details are required), delete the Sennheiser app and just use TIDAL itself.
Apart from being free, you're gonna want to ask why this over Google Play Music or Spotify (I did). The guff from the site says:HiFi Vs. Premium Subscriptions
What is the difference between a HiFi Subscription and a Premium Subscription?
With a TIDAL HiFi subscription, you have have the ability to stream 40 million tracks in lossless quality. Lossless content is CD quality music meaning that the files are not compressed, so that you hear the music the way the artists intended for their music to be heard.
With a TIDAL Premium subscription, you still have access to over 40 million tracks, but you are restricted to only High quality. This means that the maximum quality is AAC 320 kbps.
What else is included?
In both HiFi and Premium subscriptions, users have access to nearly 130 000 High Quality Music Videos, with no ads. Also, users have access to our curated editorial content, so you can learn more about your favorite content, read artist interviews, and experience hand crafted playlists from the editorial team and artists themselves.
Bear in mind that as this is far higher quality than the other subscription streaming services, it eats a lot more data so make sure your plan has enough or you have access to WiFi.
If you're using the free earphones you got free with your phone, you probably won't notice a difference in sound quality. If you're using a DAC and a decent set of cans, you probably will. Having said that, three months free is three months free, especially if you've had all the other free trials.
You can cancel the subscription immediately so don't have to remember to cancel and get stung.