Question [Q] Download Manager

I am looking for a download manager for my Nexus 5 Phone running on Mahdi ROM and Code Blue Kernel. When I download file from Chrome and/or mozila the file is downloaded at very slow speed. So, is there any download manager (Best Ones), which I can use to download files. Most of the times the files are ROMS (Zips) and/or MP3 songs. I did tried all Download Managers in Play Store, but none of them is good and are very-very complex.