Ask HN: How do you (what do you use to) show your app/product to clients

I wanted to show most of the important features included in the web application I made to remote clients and a public website wasn't an option for me (it had to be private).

I could go for a share-able Google Docs/MS-Word document with screenshots and descriptions, but that would be too primitive.

At some point I went with screen-casts, but proved to be time consuming, specially to accommodate changes.

What do you use and how do you showcase your product?