We get most of our information direct from CDOT (Colorado Department of Transportation). They have signs and sensors throughout the state and they include those from a few of the major municipalities. We augment this with Google Maps using their Directions API and weather is pulled from Weather Underground.
The data for the app is updating constantly. As long as your device has net access you will get the latest speeds and signs and cams and weather and everything. We are only putting information in the app that is changing automatically.
This entire SPA (single page application) application was built by Kevin Lee Quinn and Radd Berkheiser. Radd did the logo work and the fantastic CSS. Kevin did the HTML, JavaScript, Firebase, Google Maps integration, build tools, and back end Python scripts to keep the data updated.
All JavaScript is custom. The only libraries included are Google Analytics & Maps, Firebase, FastClick click buster, and Swipe for swiping through cameras. Transitions and routing are home cooked for speed and purity.
Of course this site is available as an app for iOS and Android as well. The interface is identical given that the native apps are just showing you this same progressive web app. We use Phonegap Build to generate the appropriate native wrappers with geolocation, push notifications, offline capabilities, etc. They are not in the stores, but you can download and install for Android here. iOS works great but requires your UDID.