Horrid. Doesnt work.

This app simply doesnt work. Set your country code in settings. Click the apply to all contacts and nothing happens. Hmm, maybe try selecting only a few contacts. Nope, when you select a contact or two and click apply to selected app, youre forced to create an account or login to Facebook. No thank you.

First time I will ever be asking Apple for an app refund.

MacMAML about PlusOne - Country Code Address Book Converter