Great App, But... – Marvin Classic - eBook reader for epub Review

This is by far my favorite app for reading epub format books. I use it every day. It is what made me realize how superior the epub format is over pdf. That said, there is room for improvement: 1. The developer has apparently written several epub reader apps, each of which must be purchased separately. It is not at all clear what the differences are, nor if they are significant. The developer should post a simple comparison of the various epub reader apps he/she has. 2. As far as I can tell, ALL of the developer's apps provide a way of extending the commands. However, NOWHERE is there a description of how to do this. Apparently the programmer thinks everyone knows how to do this, so there is no need for any information. Not so. E.g. I would like to underline words/phrases/sentences. How to do this ? Your guess is as good as mine -- or perhaps better, since I have not been able to do this. 3. The developer has provided many "cute" alternative views, color schemes, etc. MUCH more useful to me would be a wider selection of colors to use for highlighting, UNDERLINING, etc. I really do not need mauve letters on a peach background. A much more useful set of features is available in iAnnotate, which is one of the best pdf readers. E.g., you can choose from an infinite color palette for highlighing and/underlining. Unfortunately, pdf files to not provide the simple functionality of easily changing text size and reformating the page. So, you are either stuck with the limited feature set of Marvin -- which I do love, despite my critical comments here, or a fuller feature set that only works for pdf files. 4. It would be good to have a simple converter from pdf to epub and back, but that is apparaently not so easy to write.
Review by Exasperatd on Marvin Classic - eBook reader for epub.