If you can not find your app on the mobile device first make sure you have completed the creation process by clicking 'Create and start using my app'.
The search function can be found in the left menu on your device (1).
Type the name of your app into the search box (2).
After a few seconds Apps matching the typed in name will display in a list (3).
You can find a link to your app in the email you received from 'firstname.lastname@example.org'. (Please check your spam folder.)
Click 'Start you App' on the device you want to run your new app.
My Apps View
All created Apps are listed in the "My Apps" View on your mobile device.
Eventually you have to Check for Updates first.