This question is aimed mostly towards startups and product makers, but any and all advice is most appreciated: While crafting the decisions that inform the flow, customer journey and state of a product (let’s assume it is a digital one), what kind of documentation do you create to do the following:

1. State vision/purpose of a certain component or decision
2. Articulate the flow or sequence of events that are likely to happen in this scenario.
3. Capture wireframes, designs and specifications to implement this design

{I’m aware of LayerVault’s offerings, and have also used Dropbox and Github in the past: my question is tailored towards a system used in conjunction with any of these, but also how/why you use it rather than what tool it actually is}

Thanks!

A