I had previously used a One X with unity remote and had success but my phone had broke so I bought a OnePlus One. I have debugging mode turned on for general and networking yet nothing happens when I hit play in unity.
Same here 
I really want to have this work given that I have a super cool interview for a virtual reality multiplayer game next week ._.
I tried every combination, all relevant options like usb debugging are set (tried turning off mtp etc.), I can deploy and start the apk from unity editor through “build and run” no problem but the remote just wont work 
DOH got it working, just launch the app BEFORE unity editor, otherwise the editor will not pick up the remote’s presence, explained here Unity Remote for Android not working (solution) - Questions & Answers - Unity Discussions