In my experience it didn't make a huge difference. More than half the time the individual didn't even want to see it. Just wanted to talk about how it would improve their business.

Yeah it takes a lot less time to have a conversation than to build an app.

Makings the cold calls and cold emails felt a lot easier with an app built but at least in my experience didn't make a big difference in response rate.

The best way is to have that problem yourself while working in at an ideal customer.