Not sure this is the right place to post:
Remote community wants to suggest occasional/irregularly scheduled Minyanim (e.g. for Yahrzeit) and get an idea how many members can commit to coming. It’s international, so the OP’s solution probably won’t work.
The concept is for members to get a notification on their app of proposed minyan date/time and accept/decline, and see a current tally of accepted/declined members.
The solution has to be very secure (safety is a high priority for them), cost effective, and user friendly. Anyone know of an app out of the box that’ll work for this? Something that functions like a Facebook event but is secure and not posted on the public internet.