jamie@phoenix:~/Downloads$ sudo snap list ubuntu-clock-app
Name              Version     Developer
ubuntu-clock-app  3.6+snap3   ubuntucoredev
ubuntu-core       16.04.0-24  canonical
jamie@phoenix:~/Downloads$ sudo snap install ubuntu-clock-app
error: can't install "ubuntu-clock-app": snap "ubuntu-clock-app" already installed
jamie@phoenix:~/Downloads$ sudo snap remove ubuntu-clock-app
[\] Remove snap "ubuntu-clock-app" from the system
jamie@phoenix:~/Downloads$ sudo snap install ubuntu-clock-app
error: can't install "ubuntu-clock-app": snap "ubuntu-clock-app" already installed