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Chrono is a simple chronometer with a lap counter, built to highlight various aspects of the open web app development process.

View on the Firefox Marketplace.
Read the full developer walkthrough.

Difficulty: Easy

Code Breakdown:

  • 7% HTML
  • 11% CSS
  • 82% JavaScript



Web API Usage

Chrono does not require a network connection to run.
Open Web Apps
Uses the Open Web Apps installation API to allow installation on the device independently on Marketplace.

Custom Elements

Gaia Building Blocks
Chrono uses the same UI components as the built-in apps.

Third-party Libraries

Uses a volo.js script to optimize app before release, i.e. by auto-generating an appcache manifest.
Uses jQuery to simplify common tasks such as DOM manipulation.
Uses RequireJS to split JavaScript code into more easily maintainable modules.