Windows app: http://www.bwmonitor.com/ has worked great for me for a long time. Obviously, it's just for the current workstation not router.

On your budget, I'd suggest you consider a Philips SPC900NC webcam (the successor to the popular Toucam). It's $100. It comes with software. You can use various free stacking software. There are loads of sites that coach you on the easy mods you can make to the camera itself. You can't do extremely long exposures, but you can get a lot of good experience and great pictures. Maybe you want to do quantitative photography rather than just pretty pictures? Think about doing amateur spectroscopy. You can pick up a Rainbow Optics grating for $250. All the software you need is free. It and the Philips, and an inexpensive scope and a cheap mount is all you need to detect the composition of stars that are many light years away! Light pollution and "aperture envy" are minimal. Or, (and I doubt this is what you had in mind either) consider solar observing. (You don't have to sacrifice your sleep for it!) I the past few years, Coronado's PST (for $600) has made good solar observing possible on a budget. You can use the Philips camera on it too. Yes, these are all somewhat different answers than what you were looking for. But, it's where I'm focusing my time now. Good vendors: astrovid.com, OPT, Company7.