With FDA clearance you're allowed to brand and advertise your product as a "medical device". Also, without FDA approval, you have to be very careful about certain terms you use to describe your product's features. For example, without FDA approval, you cannot say your device "monitors" falls. You can only say it "tracks" falls. There are several other limitations because the FDA doesn't want you making these types of medical claims to customers unless the FDA has approved them.

Source: I worked on a fall detection app for the Apple Watch last year.

With a prescription you’ll be able to use HSA/Flex Spending or insurance to buy one.

"This feature has received clearance from the US Food and Drug Administration, meaning it can be used as a medical device — a move that is part of Apple’s increasing push to brand the watch as more than a fitness device." - https://www.theverge.com/2018/9/12/17850660/apple-watch-seri...

It is not easy to get any FDA approval. Companies go bankrupt after spending millions and still don't get approved.