HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
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.
WebCopy - Cyotek WebCopy is a free tool for copying full or partial websites locally onto your harddisk for offline viewing.
Slack - A messaging app for teams who see through the Earth!
GNU Wget - GNU Wget is a free software package for retrieving files using HTTP(S) and FTP, the most...
GrowthList - A crowd-sourced list of growth hacks