Thanks, Gwilym, but I think the mistake was Apple’s, not yours. As I wrote originally (above) I did see version 0.9.5 in the App Store last week, and it said that it had been updated the day prior. Version 0.9.4 is from September. Thanks for info on the developer. If the description of the update does not address the problem cited by the negative review for 0.9.4 I will write to the developer before updating.
By the way, I appreciate the fact that the app does not nag for reviews, so let me take this opportunity to ask fellow users to please give feedback on the app, either in the App store or here on the forum. Specifically I am hoping people will review the performance of the app itself. No need to say the lesson content is great; everybody knows that ! (well, if they are forum users they probably do know that)