In reply to Lion Bakes:
St. John's have one, too.
Both are, sadly, very much 'books', and miss the opportunity to provide computer-guided emergency triage. You have to have had some training in the first place to make use of both apps.
My experience in first aid training is that the exercises are very revealing, and probably the most valuable part of the course. I knew most of the theory in advance, but actually trying to apply it, even in simulated scenarios, was pretty hard. The actual techniques were fine, but the incident management was the thing I found hardest, trying not to get tunnel vision on the casualty in hand.