My partner and friends are competitive rowers. If the weather is not too wet or windy, early in the morning they meet at a nearby lake for training. At 4am, it's too early to phone or text other participants for a discussion about the weather. Because we live closest to the lake, they all phone us. It gets very unwieldy and wakes up whole families. Is there an app which each potential participant could use to register their intention to be there? They could check a Yes or No box. Others could run the app, see a list of names with a Yes/No flag beside the names and decide whether or not to join them. A Yes indication next to my partner's name would also indicate that weather conditions are okay. An app that approximates my wishes would be really handy for groups that train early in the morning, or anyone who arranges ad hoc meetings. Suggestions welcome. Bobster.