I'm a medical student and all of our notes are posted online in PDF format. I really liked the idea of having the notes and being able to annotate them and have seamless syncing of the notes between my iPhone (on the go) and macbook air. I just learned that just to annotate PDFs, I would need other apps and that iBooks or preview or whatever Apple puts on there originally does not support annotations. I wouldn't mind downloading other apps, but then I realized certain apps handle the using of a stylus in different ways and that this also affects everything. Are there any good options out there, by big reputable third party programs? I hear evernote is great but this doesn't support pdf annotations either, right?