I just went to Tom Sawyer today and tried out the UsynligO app and it worked very well. It was slow to buzz at the first control, but at the rest it buzzed on my approach to the control point. I liked that it told you it found the correct number, and what the next number was.
The app was simple to use. To set-up a course, it looks like a meet director just exports a Purple Pen .xml file into it - simple enough. The app works on both Apple and Android. The catch will be how do we keep the product (the map) protected for paying participants.
I think we still need something physically there to give the added "excitement" that I am in fact at what I was looking for that we all need - be it an orienteering flag, or an ammo box in geocaching. For that, I suggest we use flagging tape. I liked Chris' idea for playing cards at first, but I think if they are out there for a week, they could get soggy, blown away, or people think someone is hanging junk and takes them down. Remember, the beginner course is easy and probably near trails or common areas the general public would see. The other nice thing about flagging tape is it "looks" like it is supposed to be there in a forest - people think that the rangers or grounds crew are marking something. The meet director pulls the tapes after one week.
To deal with the GPS not working correctly, or for people who just can't figure out the app, I would suggest leaving a long tail on side of the flagging tape, and tie 1-6 knots spaced out down the tail. The number of knots would be the check number that the participant can write down to confirm that they were there. Each control does not need a unique number, like 101, 102, etc. These are just a poor man's old school pin punches that only the meet director or results chair know the correct number number of knots per each specific control.
For reporting, the UsynligO app allows you to export the total results with splits in .xml format. And we can still use Routegadget for uploading GPS tracks, which UsynligO will be able to export GPS tracks from the app.
OCIN is using a simple Google Form for completion submission on their website - maybe we have this option for the people that had trouble with the app and are submitting manually?
But overall, I like the ease of this app.