So I finished the psychic tester app this morning. My phone is an original SE, so I don't have 3D Touch available, but I do have a 4th-gen watch attached to it, so I was thinking that could be a fun option to test out. Whenever I try running it, however, the Xcode console comes back with the following:

Project 37 - Psychic Tester[5048:1555957] [WC] WCSession counterpart app not installed

I've checked the code all around and it appears to all be in order. I've also gone into the Devices list in Xcode, and while it won't let me specifically add my watch (that I've seen), I can see it listed under the SE's profile. Going into the Watch app on my phone, there's no option to install an application for the project there, either.

Any idea what else to check? I've tried resetting both devices and restarting Xcode, but the problem is persisting.