HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
Sensor Tower - Sensor Tower is a platform for app store optimization and app industry intelligence.
WebCopy - Cyotek WebCopy is a free tool for copying full or partial websites locally onto your harddisk for offline viewing.
App Annie - App Annie is a marketing analytics tool available for apps of all kinds. With App Annie, you can track sales, traffic, and a variety of other factors pertinent to monitoring an app's trajectory.
GNU Wget - GNU Wget is a free software package for retrieving files using HTTP(S) and FTP, the most...
appfigures - Cross-platform app store analytics for all of your mobile apps.