Well early I was using uc browser for downloading . Most of the time Ucbrowser works at background without even using it. Hibernation is also not working with it. So decide to uninstall it .
But comparing with other browsers, uc is top in downloading speed, no other browsers can give that downloading speed. That's why I'm looking for download managers. Download managers can give speed like uc.
Download managers like ADM has same speed as uc but it's not open source.