I will tread lightly on this topic and provide some general concepts that I have observed in the past.
From an engineer perspective, the off-canvas side menu or the 'hamburger' menu button is a great asset. Due to it's vertical nature, ability to contain sub menu items, and it's ubiquity in native apps, it's a very good option to use. Unfortunately there's a small set of UI/UX designers who take an extreme position against it, who believe it's a lazy effort. I very much disagree with this extreme position.
Indeed, the off-canvas menu can be abused. It's not needed if an app only has two items in it. It's also wrong to have 10 screen scrolls of options in the menu.
For a financial app, it is required. Don't just think about your typical single credit card user. Overtime, you'll find a need to support dozens of features for complex customers, which includes multi-TIN business owners, multiple demand deposit accounts, multiple credit cards, global investing, trading, bill pay, etc., etc., ...it becomes very difficult to limit customers to a 5 tab control bar.
In my experience, both design and product teams focus on iOS first. That's fine. Unfortunately, iOS designs don't exactly fill the void for Android engineers. There are many peccadillos betwen Android and iOS ecosystems and teams need to provide requirements and design assets with Android differences in mind.
Android and iOS are converging: Thankfully, Android and iOS continue to converge in hardware and UX. This is a good thing and should help Product and Design to deliver a consistent feature set across platforms.