I was most annoyed to see this crappy, scribbled notice stuck to the Sainsbury's car park ticket machine the other day. I decided to chance it on the basis that it would take me more time to download the app and do all the necessary stuff than to actually go in and buy the 3 things I needed.
I also felt no inclination to stand in a public place and read out my credit card number over the phone.
My bad-tempered mood and determination weren't helped by the fact that this is hardly any kind of official notice, so I felt very little inclination to comply with what is little more than graffiti.
Also, a woman in front of me said the RingGo charge was 21p - but as the ticket machine says the first 2 hours are free, I felt that that there wasn't proper notice of the charge so again I felt angrily righteous in taking my chances.
Got away with it, fortunately - but I'll admit I've downloaded the app to my BlackBerry this morning. Just in case I'm not so lucky next time.
Reading further up the thread, apparently 20p of the charge is for text alerts or text confirmation.
Edit: Heck and blast. I've just looked more closely at my own photograph. At the bottom of the official parking notice it says "Please use other machine or pay by RingGo if this machine is broken". Grrrrr. Still annoyed that you have to have a working, charged phone with you just because their machines are broken.