have used this in conjunction with the steam controller, is actually pretty nice if i just wanna lay in my bed and play some games from my phone instead of sitting at my computer or television (I also have the steam link hardware). Depending on how it performs on your phone (works great for me, original Pixel XL on 5G 802.11 a/c) this has a ton more utility than the regular Steam Link, with its only practical use case being wanting to play pc games on your living room/bedroom television. Also really happy to see that Valve haven't introduced a paywall or restricted support to only the steam controller, gives lots of accessibility to the use of the app to the point where other than the use case I described above the regular steam link hardware becomes inferior (assuming your phone is capable of streaming the games and you have a 5G connection).
Does anyone here have the Razer phone, and if so, do they know if you're able to uplink 120fps from the steam link app? That would be an incredibly neat combo of hardware/software.