I tend to be sceptical of so called boosters as your Internet speed depends on a few factors (Broadband - how far you are from the exchange, software installed on the Computer, the quality of the line, time of day) my download can vary from 8mb to 18mb in the same day and speed tests can vary from test to test, i have just used the one Clifford used >
If you go into your router settings it will show you what down and up speed your router is receiving at that time of day and that is what you should be getting within about 1mb.
Port forwarding will speed up some types of downloading (eg) uTorrent >
But all in all Internet speed boosters don't do that much.