In order to install your test app on an iOS device prior to submitting it to the Apple App Store, you must first define that device as a test device in the iOS Dev Center.
1. To login into the iOS Developer Console go to <https://developer.apple.com> and click Account at the top
Finding the device UDID
In iTunes, you can find it when your iOS Device is connected to the computer.
- Open iTunes.
- Select the device when it appears in the top left.
- Click the Summary tab in the left column.
- Click the line that says 'Serial Number' and the UDID Identifier will appear.
- Choose 'Edit > Copy UDID' to save it to your clipboard and then you can paste it into your Developer console.
Adding a new device to the Ad Hoc Profile
1. Go to the iOS Provisioning Portal and click on Provisioning. Select the Distribution tab.
3. Click the "+" sign and enter the device's Name and UDID.
Once you have completed this step for ALL of the devices you want to test with, you can create your Ad Hoc Provisioning Profile by following this article - iOS - Creating an Ad Hoc Distribution Provisioning Profile