First of all before you choose apps as your downloader / accelerator.
because those downloader/accelerator did
just to boost your basic
dowload speed that you've deal with your ISP.. therefore check your
Real download speed
here, to test your Ping/Jitter time here
and also check if your ISP throttle or shape your traffic/Bandwidth
here
for
HTTP you should check your
port 80, for
torrent thick on test page
Bittorent
After you sure your ISP not doing BAD and your Ping and Jitter test are normal
then you could choose Download accelerator..I recomend
IDM (Free version)
or
XDM, tested couple days ago same and similar with idm.
Sample my download speed
here, and sample of the good Ping time and Jitter
here
I hope you will not confused wih my explanation in my own words...Good luck.