I had one disappointing/embarrassing experience in writing this blog over the past three years, which was a war of words with a developer regarding the feature of annotation in PDF music readers. The app in question was iGigBook, which has been a popular PDF music reader for gigging musicians.
Regardless of my past interactions with the developer, I thought it would be important to mention that the latest version of iGigBook includes annotation. As I’ve stated repeatedly, my opinion is that annotation is an essential/required feature needed by a musician (whether a pro or a student). iGigBook has added that feature, and therefore joins the ranks of PDF Music Readers that have the core features that are needed by musicians (along with forScore, unrealBook, Deep Dish Designs GigBook, and the new Gig Easy app).