Apps - Security ???
As most mobile phones are running old versions of software for which no upgrades are possible (eg my Android phone runs on 4.2.1), the platform is insecure. It does not matter how good the app is if something in the background can intercept every keystroke/finger tap. In my opinion mobile phones are unsuitable for banking. (To pay for apps on the Play Store, I use prepaid Play Store gift cards - there is no bank or credit card usage on my phone at all.)
An app running on a PC or MAC with the latest security updates and a good antivirus package MAY be secure, however I trust Firefox with Noscript and AdBlockPlus more than an app written by a bank that probably got its code written by the lowest bidder in India.