The most useful function is the automatic update system which allows me to easily make changes on my proposal, without having to go back and forth from a word document. Sometimes it's hard to find what you need when you're using a lot of tabs or features, so it would be great if there was a search feature where you could filter by title or tags. I also think they should include some sort of template to use as a starting point for proposals. With the automatic update feature, it makes it easier to stay organized, since I'm able to add new requirements or updates to my proposal without having to send an email to the client every time something needs to be changed.