App for improving network speed?

I've got this weird thing going on lately. Whenever I download a file, no matter 100mb or 10gb, no matter if the DL is going "full speed" or not (i'm on a 40mb connection). The download speed regularly "peaks" either at my own maximum download speed, or at the sending server's maximum upload speed. It then drops down to less than half of that, and after a while it peaks again, etc.

Basically my problem lately is that, no matter what the download speed I'm getting, it won't stay consistent. And this happens when I have multiple downloads on too.

example: downloading a 4gb game on steam: http://i.imgur.com/u7s5H.png

example: downloading something on uTorrent: http://i.imgur.com/IFTVn.png

So to the main question. Is there some software to improve/bypass this network behavior? Somebody suggested something like CfosSpeed, but that's unfortunately PC-only.. Thanks!