Many different mobile wallets have been developed. There is a Bitcoin wallet available in the Google play android app store by doing a search for Bitcoin wallet. It is a good choice for non-technical people, and it is also available for Blackberry.
Several Bitcoin apps in the Apple app store are so new that we have not been able to evaluate them yet. Coinbase did have an Apple web wallet app which did not store anything, but it was recently removed for reasons unknown.