Our gliding club is small - and thus communication between the members is critical. We have two WhatsApp groups - a general one as well as one specifically for committee members. The general one is related mostly to the weather outlook for the weekend, and who is planning to fly etc. The committee one is more about the administration issues for the club. Most people have their cell phones with them all the time - and WhatsApp does not need to be specially logged in to view messages etc. It works for us.