Form Animation in Photoshop

I've been experimenting with a few prototyping tools. Part of my role as a designer/developer is to communicate efficiently with my team, developers, product manager, marketing etc, so that we can bring to life a product people love. Prototyping will help us share smal details, microinteractions, to big layout interactions so I decided to learn a prototyping tool. Photoshop has the animation timeline built-in so I've been playing with it. I'm not proficient with it, and found it to be a fair tool for prototyping. One thing I struggled with was making type animated since it requires separate layers for each letter, but it's working. What do you think? What are you using for prototyping? What tool do you use for prototyping?