the latest Android Platform Tools and try again.
You're using an old adb.
Alternately you can transfer the apk to the watch and then install it from the watch
adb -s 192.168.1.207:5555 push Watch.SHM.MOD.126.96.36.199.apk /data/local/tmp/Watch.SHM.MOD.188.8.131.52.apk
adb -s 192.168.1.207:5555 shell pm install /data/local/tmp/Watch.SHM.MOD.184.108.40.206.apk
Note: You can also download the app from my signature and use the Install APK feature to Install.
You don't need to care about other aspects of the app.
There is also a crude Package Manager in there that will get better in time.