For years now many of us have used online banking as a method of checking balances, transferring money and paying bills. Most banks have some sort or secure log in systems to make this possible, but many have also invested in apps for smart phones and other smart devices such as tables. These apps can often be downloaded for free and linked to your current and saving accounts. They will instantly show you a balance and most of them also allow you to make simple transaction (such as paying a person you have paid before). Some of them, such as the Nationwide app, remembers your details and will display your balance simply by clicking one button, without having to log in.
As with all things online, I you are using the internet to carry out banking, make sure you have a secure connection and that your device has an up to date antivirus software package installed.