RaceJoy is one of the coolest mobile apps for races. They do a bunch of different things, but the really unique feature we like is the GPS tracking capability. The basic idea is that a runner in a race with a mobile phone can share their position with others.
I used this last year when my daughters ran the Cherry Blossom 10 Miler. With 20,000 runners, it is tough to spot even your own child in the crowds. With RaceJoy, I was able to see their little blue dots on the course map moving to my cheering position so I would know when to get to the front of the crowd and cheer!
RaceJoy is different than Garmin, RunKeeper and MapMyRun (and is not trying to replace them!) in two ways. First, it is sharing the GPS position continually during the race. Running training apps will collect your GPS position as a set of points on the phone and then upload that data when you return from your training run. Second, for RaceJoy to work properly, it must know the course map exactly (this can be uploaded to RaceJoy in various ways for free). So if RaceJoy sees you at a certain latitude and longitude (how GPS data points are kept), it knows where you are exactly on the course (well, within 10-25 meters). This opens up a lot of possibilities in the future for further enhancements to the RaceJoy app.
Any race can be “RaceJoy-enabled” for free! All you need to do is send your course map to firstname.lastname@example.org. You can send it in an electronic file format (KML or GPX) or send a link to wherever it is stored like MapMyRun. Once that is done your race is listed in RaceJoy within two weeks and your runners can decide if they want to be tracked and spectators can decide if they want to track some of those runners. And the cost of 99 cents is well worth it for the runners and spectators! (You will want to make sure you highlight this in your website, confirmations, email blasts and so forth).
The Space Coast Marathon made RaceJoy available for their participants and over 15% of runners enabled tracking with about 2-3 spectators tracking each RaceJoy runner. This is obviously not a replacement for timing systems, but can bring a lot of extra value, convenience and fun to your race.