In addition to all the steps described in the Official ConnectIQ iOS SDK Guide, gcm-ciq application query scheme needs to be added to the Info.plist like so:
<key>LSApplicationQueriesSchemes</key>
<array>
<string>gcm-ciq</string>
</array>
Make sure to match watchAppUuid with the one from the ConnectIQ app manifest.xml.
urlScheme must match the value specified in Info.plist.
For some unknown reason, ConnectIQ iOS SDK REQUIRES your app to set "Bundle display name" (key CFBundleDisplayName in Info.plist) or the device selection just up and fails.
If anything's not clear enough, consult Official ConnectIQ iOS SDK Guide.