The very next step we always take when designing a product is to get the wireframes onto a mobile device. We use a tool calledInvisionthat allows you to not only preview your wireframes in a browser, but also download a prototype to your phone.

As a designer, you are able to upload your screens, menus, loading screens, icon, etc to Invision and then create hot-links right on top of your designs in the browser. From there, it's as simple as e-mailing out a share link (public or private), and getting feedback.

The point here is to make sure that you're starting to get an idea of what it's going tofeellike to your users, end-to-end. This will let you spot gaps in the experience sooner and begin to give your developers confidence in their understanding of what is to be done.