Here's a quick video showing you how to Install Pencil:
Go to my.pencilapp.com and log in
You'll see a series of icons in the right hand side of your browser's search bar
Click on the “Install Pencil” icon located to the left of the “Share” icon.
Once you’ve clicked on this icon, a pop-up window will appear that asks if you want to install the Pencil app. Click on the blue “Install” button to confirm the installation.
After confirming the installation, the Pencil app will automatically open and close your tab. You will be able to find the app via a desktop shortcut on your home screen, making it easy for you to instantly access Pencil!