QCrash allows you to join queues from distance. Say you want to go to a government office, a hairdresser or your doctor, with QCrash you can join a queue without going there or calling. Then, when the appointment time arrives, the app notifies you in advance.
Some of the queues you’ll find will require an appointment at a specific hour. Some others won’t, as those are “first come first serve”. In any case, you are notified of the delays or gains so that you always have an updated appointment time as the queue progresses.
At the end, you are there for your appointments just at the right time, without having to wait for hours at crowded locations.