Quick tutorial on how to get started with your Garmin ANT+ Adapter for iPhone.
There is a QR code on the back packaging that you can scan. This will take you to a webpage which basically tells you to download from the App Store; the Garmin Fit app. Which should be 1.99$. Once you download the app, you can plug in the adapter and scan the iPhone for your ANT+ device such as a heart rate monitor, footpad or bike accessory.
Once your sensor has been detected, you can go and setup your Garmin Connect account info and start a new activity.