Application like iStat bandwidth function for router

I'm looking for an iStat-like application that I can use to monitor my total downloads from my router. My issue is that the router will flash like crazy and the internet connection will get very slow without anyone in my apartment using it. I figure it's either someone is using it and saying they're not, or there's someone out there stealing my wifi connection. I've already changed the password to no avail.

So is there a way to see the total kb/s downloading from the router rather than from one individual Mac? The router is a Linksys and we're all using Macs.

TIA