You can close your account from within the app or using the web interface when you are logged into either. In the app, go to the settings page from the home page menu at the top right in both Android and iOS apps and select the option to remove your acount. In the web interface, navigate to your profile and select the 'remove account icon on the top right hand side of the view. Hovering over an action button shows you its description.

One removal is confirmed, your account is deleted and personal data is removed. This cannot be undone. If you are the sole administrator for a community, this community will also be deleted. All personal data associated with your user will be removed within 30 days of removing your account.

Communities may retain member records indpendently of real users but to do so provided they have a valid privacy policy shared with their members that describes their use of member data. Deleteing a user acount that you have created and linked to a community will not remove any data that the community has created itself but will remove any date that you yourself have shared with that community. You can ask a coimmunity to share the data that it holds about you and to remove your personal data.