Problem is
1:Visit a house or apartment that have problem with walls or floor (kitchen,room or toilet)
2. Make the picture or video of the problem
3: Make diagram of the problem for example. toilet( length and Breadth). mark the problem area
4: Develop this in Mobile view
I have test step 1 and step 2 in PowerApps. Now making diagram of the toilet or kitchen and embedd it PowerApps or a separate app in JS that make diagram separate and then load in PowerApps and combine (Pic and Diagram) in the final rapport .
BPMN is not about toilets or nyan cats. It’s about process automation. I still don’t see the connection. You might want to look for a more generic diagramming tool. bpmn-js is a domain-specific tool.