Is there a tool that shows dimensions during editing?

Question

Is there a plugin or tool providing following functionality:

1. I select 2 points (or vertices) - it shows the length between this points.
2. When I edit the point (or move vertex) the length automatically updates (allowing me to easily move point to the distance I want).

I know there is dimensioning plugin but I think it is not what I want and it is not working well in 2.6.1.