Ideally you test on both a newer device as well as older. Makes sure it works acrosss versions.
I’m just trying to get a minimum viable product/prototype together at this stage, so hopefully I can actually pay a programmer (or a few programmers) to make it compatible with as many devices as possible, as well as secure etc. I know as a rookie I absolutely do not have the capacity to build the exact product I’ve got in my mind, but I at least need something tangible to add to my pitch. I appreciate the insight though!