Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
GoodGantt - The best Gantt chart for Trello®
SiteSucker - SiteSucker is a Macintosh application that automatically downloads Web sites from the Internet.
Paws for Trello - The best way to use Trello on your desktop
GNU Wget - GNU Wget is a free software package for retrieving files using HTTP(S) and FTP, the most...