The technology stack followed modern web app architecture that we are very comfortable with.
We created a responsive web front-end using Bootstrap and AngularJS.
The hybrid iOS application uses the same front-end code than the browser version. The wrapper was done with XCode, using only native Objective-C based components. The app was optimized for iPad.
The back-end system is programmed with Python, using Django framework.
The system has an admin panel, where the calculation formulas can be adjusted easily. More energy usage data from actual buildings can also be imported, which makes the calculations increasingly accurate.
The service runs on AWS cloud.