Be proactive in protecting the mobile device itself.
Depending on what security options are available on your device, create a "strong" password (consisting of unusual combinations of upper- and lower-case letters, numbers and symbols) or PIN (with random numbers instead of, say, 1234 or the last four digits of your Social Security number) and periodically change it.
Be careful about where and how you conduct transactions.
Don't use an unsecured Wi-Fi network, such as those found at coffee shops, because fraud artists might be able to access the information you are transmitting or viewing. Also, don't send account numbers or other sensitive information through regular e-mails or text messages because those are not necessarily secure.
Take additional precautions in case your device is lost or stolen.
Check with your wireless provider in advance to find out about features that enable you to remotely erase content or turn off access to your device or account if you lose your phone. Quickly contact your financial services providers to let them know about the loss or theft of your device. Notifying your bank quickly will help prevent or resolve problems with unauthorized transactions.
Research any application ("app") before downloading it.
Just because the name of an app resembles the name of the bank -- or of another company you're familiar with -- don't assume that it is the official one of the bank or company. It could be a fraudulent app designed to trick users into believing that the service is legitimate.
Be on guard against unsolicited e-mails or text messages appearing to link to a financial institution's Web site.
Those could be "phishing" messages containing some sort of urgent request (such as a warning that you need to "verify" bank account or other personal information) or an amazing offer (one that is "too good to be true") designed to lead you to a fake Web site controlled by thieves.
FDIC Consumer News. Winter 2012/2013. Safe Mobile Banking: Our Latest Tips for Protecting Yourself. www.fdic.gov.