Notifyr shows all your incoming notifications from your iPhone on your Mac.
If you find the screen on your Apple Watch is too small, use your Mac to see your notifications.
Requires companion OSX App from: http://www.getnotifyr.com/
US was $4.99, AU was $6.49, now Free.
US store link: https://itunes.apple.com/us/app/notifyr-receive-ios-notifica…
I was under the impression that iOS already worked seamlessly with iOS. You get notifications, and can respond to them (eg text messages) right through your mac? Or at least that was the benefit one of my mac friends was telling me to go 'all apple' (I currently use an Android with pushbullet for the same functionality)