The fundamental problem with self-refereed Rock Paper Scissors is the disputed throw. Was the reveal genuinely simultaneous? Did one player commit late? The argument about the argument is often worse than just flipping a coin would have been, which defeats the point of using RPS to resolve something efficiently.
The Referee app solves this. Each player registers their throw on the screen before either is revealed. The app handles the timing, the simultaneous reveal, and the outcome determination. There is no ambiguity about what was thrown when. The result is final and visible to both players on the same screen.
This is particularly useful in the specific scenarios where Rock Paper Scissors is most valuable: the quick decision between two people who both need to be somewhere, the tie-breaking moment in a situation with actual stakes, the case where someone needs to know the result is legitimate rather than susceptible to post-hoc challenge. The app's function is to remove the social friction from the game's most useful application.
The WRPSA's Referee app also logs results if you want to build a record across multiple decisions. Some people prefer to keep this data. Most don't. Either way, the throw was fair.