TL;DR
Head over to PhoneLink VR's properties in Steam, go to the beta tab and select "redesign-preview". Let PhoneLink VR update and enjoy! (you may need to restart Steam if you don't see the option).
We can't wait to hear what you have to think about our new look in the comments!

The longer bit
If you've been keeping up with our devlogs we've been working on a new version of PhoneLink VR for quite a while. The old app wasn't the best in terms of design, so we've taken the time to rebuild the app from the ground up.
This has been a massive undertaking and we're almost finished! However we need your help to make the new version of PhoneLink VR the best it can be.
We'll be replacing the old PhoneLink VR client with this new version very soon but we're giving our users an opportunity to preview the changes and help provide feedback before we go live. All you have to do is follow the instructions above, try the changes out and give us feedback in the comments.
Changed depots in redesign-preview branch