OK, Altea Amadeus does this, and is a Complete DCS with Weight and Balance built-in. It works and many seem to like this one.
However, I have used D-Plan now called Libra for many years and is my personal favourite. It works well as a stand alone Weight and Balance system for both Narrow and Wide-Body A/C types. It is very visual and flexible, a drag and drop system and is very easy to learn. It works on a web-based server on the PC only.
I know Libra can connect with Shares DCS, you click a button in Libra to download up to date pax figures checked in, A/C bay splits and baggage data; which will indicate when the pax figure is final. I not sure if any other DCS can be connected though.
