Online banks are booming, attracting over three times as many new consumers as they did a decade ago. And Goldman Sachs is now cashing in on the action. For years, the bank has been the preserve of the super-rich, but since launching online, it's opening up to the masses.

Since the mortgage crisis, for those with bad credit, borrowing meant high-interest, short-term loans. The Build Card offers an alternative. It monitors your spending and provides payment targets, helping you develop a stronger credit score. Will it help those with bad credit get back on their feet?

People who manage their finances online still aren’t benefiting from the money they’re saving their banks. Loot wants to change this, offering students an app and debit card combined with personalised advice and retail offers. But can it really help the 80% of university-goers who fret about debt?

American Express is synonymous with privilege and luxury – so its latest venture may seem surprising. Its Bluebird Bank helps Americans let down by traditional banking, who may not even have a bank account. What's driving the makers of the Black Card to bank the unbanked?