Bruji

Do I have to use a Custom Field for this? If so, it would be nice if I could specify the data format of custom fields and make this into a checkbox instead of typing stuff in!

You have to use a custom field. We have it as a feature request that custom field formats be a preference or to add a few custom dates and check boxes. The advantage of the custom field is you will be able to do more than check it, "Reading", "Read", "Postponed", "Never going to read"... With autofill you only have to type one or a few letters to enter a full word. Thank you for the feedback.