It's not often a banking app cracks the Play Store's top 10 charts. But a relatively new app from TD Canada Trust called MySpend has found a way to cross that invisible line between utility and everyday necessity. And that's no accident.

We caught up with them to find out why.

"We've been on this journey for four years," says Rizwan Khalfan, TD Canada Trust's Chief Digital Officer. MySpend, which was developed by Philadelphia-based Movencorp and adapted for the highly-regulated Canadian market, provides instant access to customers' recent transactions across bank accounts, credit cards, and other TD products. Users get push notifications the moment a transaction goes through, along with insights on spending based on category and trends.

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But obviously none of this is particularly new. What is unique about MySpend, though, is that it was developed specifically for mobile, which Khalfan says has been the key to the app's success.

"Most competitors [in this space] had been offering a Banking Finance Manager (BFM) online," Khalfan said. "But we found that the maximum uptake was around 4 percent." He said mobile users tend to engage with their banks nearly four times as much as those on the web, largely due to the speed at which they can log in to their accounts.

The result is an app that has quickly risen to the Play Store's free apps chart, peaking within the top ten of a highly dynamic list that includes mainstays like Facebook Messenger and Snapchat. How could a banking app garner such a positive consumer reaction? To Khalfan, it was about focusing on the features that really matter to consumers.

I thought, 'Couldn't we make a more real-time service to help people budget?'

"Other products [in the category] forced people to wait until the end of the month to see trends, which prevent people from making changes. I thought, 'Couldn't we make a more real-time service to help people budget?'"

After working with Moven, the result was MySpend, which outlines spending trends in clear ways. You spent more $400 on entertainment this month, it says, which is $250 more than usual. What happened?

Khalfan notes that the app provides "soft advice" — helpful hints that guide users towards corrective behavior, rather than reprimand users for so-called spending mistakes. "You know your life best," he says. "We're not here to change you."

But working with a startup was an entirely new direction for Khalfan's digital team, which is managing the transition from retail-first to an increasingly mobile-first customer base. He says that MySpend is a plug-in that hooks into TD's growing app platform, utilizing authorization tokens from the core app to maintain security and privacy within Apple's and Google's respective silos. "We can constantly bring innovations to our customers" by unplugging older units that are no longer useful, Khalfan said. In that way, the company saves in-house development costs and gets to navigate the mobile space with more agility than typical bureaucracy-laden institutions, other banks included.

The app's success can largely be attributed to TD's growing base of 3.5 million monthly mobile users.

The app's success can largely be attributed to TD's growing base of mobile users, which total more than 3.5 million every month. "We have the best customer acquisition in the country," Khalfan continues, attributing the bank's success in the retail space to a sustained focus on physical and digital products, with an emphasis on customer service across both categories.

But the popularity of MySpend is likely much simpler than that. It's a great product that benefits everyone, not just those who use the core app to check account balances or deposit cheques. In that way, MySpend has graduated from being an app opened monthly to one used daily. And that gives TD and Movencorp the freedom to add features without concern users will abandon it for greener pastures — since they're the only pasture in town.

Download: TD MySpend (free)