Its not what you think. In the film world high concept movies refer to “artistic work that can be easily described by a succinctly stated premise.” (i.e. Snakes on a Plane). This is even more relevant to the app world where your main promotion avenue is essentially a list. Like with movies these titles should hit a resonance of popular fascination (or what we like to call a meme in the techie world). Apps are not movies so (obviously) but most the most part they are entertainment and even the most successful utilitarian apps tend to have a bit of “zazz” that gives mundane task such as converting units a fun experience.
We have talked about What’s in an Application Name before, but the modern entertainment industry has 100+ years of experience and its always good to not have to re-invent the wheel.