Ever since aviationweather.gov redid their website to be much more feature-full, I've found it very difficult to use on my very slow Android 2 phone with a tiny screen. So I decided what I really wanted was a geo-located METAR/TAF display. "Just the facts", so to speak.
I also added color-coding so that I can easily pick out the bad conditions from the rest of the data.
I wouldn't ever expect this to have a wide audience since every pilot I know also has a late-model iPhone with a variety of aviation apps. But it serves a need for me, and more importantly, it got me back into hobbyist development (at least for a little while).