Jupyter Notifier
Jupyter Notifier is a browser extension that notifies you when code cells terminate.
Description
On every Jupyter Notebook environment, Jupyter Notifier allows you to select specific cells for notification. For this, Jupyter Notifier injects a button 
into your notebook. You can get notified with a sound, a message, or both when code cells terminate.
With Jupyter Notifier, you won't be repeatedly checking whether your cell has finished running.
Installation
Jupyter Notifier can be installed through the Chrome Web Store and will be available for Firefox soon.
Screenshots
With clicking the button , the selected cell(s) will notify you on termination.
Jupyter Notifier adds an indicator next to the selected cell(s).
On termination of a subscribed cell, given 'Notify me with a message' is activated, you'll get a notification containing the runtime of the cell.
Contribute
TBD
License
MIT © Baran Yildirim