We used WhatsApp at the Region 10 contest at the Soaring Club of Houston this past week to communicate contest info, reminders, task information and weather charts. The feedback has been positive so far with one exception:

*No chit chat. Ask participants to start their own private sub-chats for topics that don't affect the whole group. A few people turn off notifications because there is too much chit chat. This defeats the purpose of timely communication of the important information.

Jamie Shore
Soaring Club of Houston