The Forerunner 110 does not have Bluetooth capabilities so you will not be able to add it to the mobile app. However, you can transfer data using Garmin Connect Web.
How can I connect my forerunner 110 to Garmin connect app?
You cannot, since the FR 110 has no Bluetooth, hence cannot connect to the phone app. You have to use the USB cable and Garmin Express, or download the activity FIT files and import them to Garmin Connect Web manually.
