Grenadine[]
Grenadine is a suite of convention programming planning software often used for Eastercons. It is commercially developed by a fan, Henry Balen, but he kindly offers a free version or reduced price version to conventions. Accessed through a web interface it allows programme scheduling, mailshots, questionnaires, and can publish to paper, a website or a Android/IOS app.
More details from events.grenadine.co