True Green Wifi. Is It Green Bangkok Free Wi-Fi. Any Good? Easy To Register?

After seeing all the True Green Wifi adverts on bus stops around Bangkok, I have tried to register my phone online, to no avail. All the info is in Thai even though there is an English translation tab at the top which must be a decorative feature.

I found some info on Bangkok Post, but no registration details.

http://www.bangkokpost.com/learning/learning-from-news/291478/bangkok-free-internet-23000-hotspots

Does any one use this free facility? I believe the free service is 5 hrs/month. If so is the service reliable? Any advice on how to register for the free service?

My phone uses a 1-2-call SIM card and I have registered my phone for 5 hours/month of free Wi-fi for AIS/BB3, but there are no hotspots for this where I would like to use it for 1-2 hours at weekends.

I know that True offer 300 baht/month unlimited Wifi connection, but I am a 'light' user and if there is a free option then it makes sense to use it, if it's any good.

Any advice?