Schrödinger's Cormorant is entirely free to use. There's absolutely no need to worry about money here.
If, however, you enjoyed it and/or found it helpful and feel moved to make a donation, that would be great. It might help encourage me to develop some more educational resources or, at least, enable me to buy a cup of tea or some treats for the labrador. In any case, there is a link to a donation page below .... if you really want to.