Dashing is a mature dashboard framework, based on Sinatra, used to build very beautiful dashboards. It's frequently used to display dashboards on TV screens in offices.

Here are the main features:

• use premade widgets, or fully create your own with scss, html, and coffeescript
• widgets harness the power of data bindings to keep things simple. Powered by batman.js
• use the API to push data to your dashboards, or make use of a simple ruby DSL for fetching data
• drag & Drop interface for re-arranging your widgets
• host your dashboards on Heroku in less than 30 seconds

The project was created at Shopify for displaying custom dashboards on TV screens.

Example 1 link - Example 2 (TV screen) link

More information on the project website.

Keen is a web-based analytics and data visualization platform that provides data collection, data analysis and data visualization solutions to business intelligence professionals. The platform can be customized and integrated with various platforms and software by using its API, SDK and third-party integrations.

The data visualization feature in Keen enables analytics professional to create, customize and embed charts in dashboards, reports, and clients facing documents.
The billing of Keen's services is based on how much new data the client collects. More information on the official website.