via: http://www.webupd8.org/2014/05/install-popcorn-time-in-ubuntu-or.html
To add the WebUpd8 Popcorn Time PPA and install the app in Ubuntu / Linux Mint (and elementary OS along with Ubuntu derivatives: Xubuntu, Kubuntu, etc.), use the following commands:
$ [sudo] add-apt-repository ppa:webupd8team/popcorntime
$ [sudo] apt-get update
$ [sudo] apt-get install popcorn-timeTo install Popcorn Time from the WebUpd8 PPA repository in Debian, use the following commands:
su -
echo "deb http://ppa.launchpad.net/webupd8team/popcorntime/ubuntu trusty main" | tee /etc/apt/sources.list.d/webupd8team-popcorntime.list
echo "deb-src http://ppa.launchpad.net/webupd8team/popcorntime/ubuntu trusty main" | tee -a /etc/apt/sources.list.d/webupd8team-popcorntime.list
apt-key adv --keyserver keyserver.ubuntu.com --recv-keys EEA14886
apt-get update
apt-get install popcorn-time
exit
@shamim2018 Webupd8 team feared legal repercussions (allegedly some people were jailed for even mentioning PT) so they removed the PPA. It doesnt work any more. The only option is to go to PT homepage and install it manually from the tar.gz file. You can search online how to install tar.gz files.