All software that claims to increase internet speed is fake....but if you are talking about downloading maybe flashget can help u. You just need to set the number of threads to maximum 10. It will get your download to be split into 10 parts and download them concurrently if the uploading website allows it. Using it on firefox with the add-on flashgot simply rocks!!!!
If you have slow internet download speed means,Try to increase your speed by using the following tips.
1.Get a download accelerator
2.Turn off all unused apps while downloading
3.Don't upload information while you're downloading
4.Update your network device driver
5.clear your temporary download history files.
6.Use latest version of any browser
When i had the same problem,i followed the same ways.I am sure,it's very useful to increase your download speed.Then you can check your new internet speed using ScanmySpeed.com