iStonsoft ePub Converter for Mac lets you create ePub files from HTML, Mobi or PDF files. ePub is a format widely used these days for e-books. The iPad, iPhone and iPod Touch use this format in their iBooks app. I personally like this format because of the features that it offers. For example, I can create notes, highlight parts of text, copy text and more with my books. I haven't found any way to do that in iOS with PDF files. So it is important that I can still do those things when I convert a PDF file to ePub with this tool. I am glad to say that during my testing, I found that the app does a great job of converting files.
I did my testing with both HTML and PDF files. Both were text-based and editable. To test HTML file conversion, I saved an HTML website using Chrome. The file was from a Wikipedia entry and the conversion process was completed quite smoothly. I loaded the resulting file into iBooks, on my iPhone, and it looked quite good. I opened it and could select text, follow hypertext links, and change the size of the text. I got the same good results with the PDF file.
You can load a single file or an entire folder to your conversion queue. This is great if you have several files that you want to convert. You can't mix formats, though. You need to select the type of file that you want to convert before loading it.
In short, iStonsoft ePub Converter for Mac does a great job of handling files and converting them to the popular ePub format. The app isn't the most affordable solution out there, but if you have a lot of books that you have already paid for and need to convert them, then the price isn't a big problem.