I've noticed some of the design conventions for iOS apps will appear on Android: E.G., Instagram uses toolbars. This also happens on iOS: E.G., Google uses material design in their YouTube Music app.
What are some examples of an app – which is designed for both platforms – that feels agnostic to either design convention, yet seems to pull it off? Thank you!
A little more backstory if needed: I'm a longtime iOS user, and now find myself designing an app for both Android and iOS. The client is requesting a more neutral UI that doesn't adhere to either OS to cut down on design/dev time.
I believe you will find a lot of examples if you search for "Cross-platform" apps. However, I highly advise you to consider metaphors that adhere to the OS. For example, most iOS users might find it hard to understand the hamburger icon. Thus, while designing, do formative testing with your target audience, just to ensure that your design has fewer usability issues before the development starts.