PresentDay is completely free to use, and always will be.
Although PresentDay was originally created to help manage Christmas lists, you can use it for absolutely any gift sharing event you like. We're also planning to add support for gift registry events, such as weddings.
Once a gift has been added to your list it can't be changed or removed as someone might have already bought it for you. Allowing gifts to be edited or removed could cause confusion for other users, or inadvertantly reveal if a present has been purchased for you.