"Hey, John, just to check if you had a chance to try Koncept? It is perfect for rapid creating of high-fidelity prototypes and getting accurate metrics on user behaviour (2 in 1). You decide which tasks you want to add to certain scenes, share the prototype with users and then sit and track precise data (task acceptance and completion rates, completion times, etc.) as well as heatmaps. There is a 7-days free trial, so be our guest. ;)"