BookFusion supports all eBook formats including epub, mobi, PDF, and comic (cbr/cbz) formats. BookFusion is a cross platform eBook app that allows you to upload, organize and read your eBooks across all devices. The app that you are looking for is called BookFusion!.
But I get a lot of free PDF ebooks, and has magazine/pulp issues as PDFs.)
(I am very aware that pdf is a terrible ebook format.
I'm looking for an app that will read non-DRM'd epub, mobi, PDF, and comic (cbr/cbz) formats. I had forgotten that Marvin is epub only epubmobi says it supports all four filetypes but I couldn't get it to connect with Dropbox's offline files. I tried Marvin and then ebookmobi, and removed them as they didn't have the features I wanted. The easiest way to get them onto my iPad is Dropbox, and it seems many readers are supposed to connect with that, but it's not always clear how that works. I have swarms of ebooks on my hard drive. I'm looking for a good app so I don't have to keep switching between different ones.
I've recently gotten an iPad and am just starting to use it for ebooks.