Manga+Press 2.8 Beta-1 is available for download from my Github page [here].
Manga+Press 2.8 brings compatibility with the new Media Library window introduced in 3.5. Manga+Press 2.8-beta1 was tested with WordPress 3.6 alpha — I haven’t had a chance to test it out with the RC version yet. Find an issue with 2.8? Please log it on my Github page, thanks!