Thanks Aniket - great overview.
Along with wireframes, I've found paper prototypes to be a great companion to storyboards for mobile. Their tactile nature is quite effective for getting a feel for how the finished product will function.
You can also use them to test and demonstrate functionality with users. It might look strange asking them to hold a 1:1 paper cut-out of a phone and then to keep swapping bits of paper over as they press imaginary buttons. However, it's much clearer and more immersive than a static wireframe.
It can be a really interesting exercise to cut a screen-sized hole and scroll content behind it on a long piece of paper to see how the composition of the page feels when you see it a bit at a time.
Lots of great video tutorials online, like this one: https://www.youtube.com/watch?v=V8LNDqMIapY