I jailbroke my kindle and this was what the guide I followed installed. I don't know what else is available!
My experience has been "fine" - I don't use anything fancy like dictionary lookup or OCR, I just put epubs/pdfs on it and browse. I find the menu UI pretty good, it's a little unintuitive but there is a short guide that covers everything I need. There is no easy way to browse your library (there is a file browser but I don't like that). Ditto I don't find browsing through a book particularly intuitive, but it has page seeking and you can scroll through pages.
My experience has been "fine" - I don't use anything fancy like dictionary lookup or OCR, I just put epubs/pdfs on it and browse. I find the menu UI pretty good, it's a little unintuitive but there is a short guide that covers everything I need. There is no easy way to browse your library (there is a file browser but I don't like that). Ditto I don't find browsing through a book particularly intuitive, but it has page seeking and you can scroll through pages.
For casual reading, I think it's just fine.