The API was shut down and the app removed from the App Store.
Bellbot may be a useful alternative.

You can trigger your Bell's ring URL with any cURL-like client.
$ curl https://api.lilbell.com/v1/ring/PUBLIC_KEY
Or, you can embed the Bell's URL as a JavaScript on any web page.
<script src="https://api.lilbell.com/v1/ring/PUBLIC_KEY/.js"></script>
And, you can do more with our API.
View the API Docs
Email us: contact@smileslaughs.com. We're on twitter: @smileslaughs #LilBell.