After workshopping with the mobile development team, the idea was to utilize the camera to capture the corners of the room. 

We sketched out initial UI concepts on whiteboard and paper, focusing on the main functional requirements of the app (capture, undo, complete, cancel, etc.). 

To refine the ergonomics of holding and using a mobile phone or tablet to capture a room, we performed a series of paper and device tests to assess where user's hands could most easily access the UI. These tests were performed with a wide variety of users to understand hand size and mobility.

This is an example of a mobile UI created to measure hand placement.

Based on the results of usability testing and continued input from the engineers developing the back-end algorithm, we began an extensive series of iterative development and internal testing. 

At a user conference, we created a usability lab where users could test the application in a variety of staged rooms. The app collected user data during the test and users completed a questionnaire following the test.

These results were analyzed and the findings were reviewed with the engineers for further bug fixing and enhancements.