Remote Linux Unlocker is an android application paired with a linux daemon that allows users to unlock and lock the Ubuntu Unity lock screen.
Install the android application from the Google Play Store or download the source from this repository.
$ wget https://github.com/maxchehab/remote-linux-unlocker/raw/master/linux-daemon/linux-daemon.zip
$ unzip linux-daemon.zip
$ cd linux-daemon
#edit `unlocker-daemon.service` so that the absolute path to unlocker-daemon.py is correct
$ mv unlocker-daemon.service /etc/systemd/system/unlocker-daemon
$ sudo systemctl daemon-reload
$ sudo systemctl enable unlocker-daemon
$ sudo systemctl start unlocker-daemon
$ ./remote-linux-pair