EasyBib has an extremely helpful mobile app....and it's completely free! The mobile app is available in the iTunes and Google Play store.
The mobile app allows you to cite in any citation style for book, journal, magazine, or newspaper source types. Export citations created on the mobile app by emailing them to yourself or another person.
Also, if you have an EasyBib account, you can login to that account on the app. A project will then be created in your account titled "Mobile Citations".