Helipaddy, the helicopter landing site app, has flown past the 10,000 location milestone with little sign of stopping as coverage expands in Africa, Australia and the USA.  Helipaddy has remained very focussed on data quality which becomes a real challenge with this many locations.  Thanks to their core moderation system, they are able to scale up without compromising the accuracy.
Helipaddy have added some interesting new features, such as the auto-logbook, which are all designed to keep as many eyeballs on the data as possible.