I have been using ipad with pencil for the past 2 years.After trying, various apps(evernote&one note),I settled withGoodnotes, which became solo companion in my Preparation.
- The interface between pencil and ipad very smooth(just like pen & paper)
- U can organize books as u like(u can delete the pages which are unnecessary)
- The global search bar which is sophisticated tool that an even track ur own handwriting.
NextLiquid textapp,which aid in making very short crisp notes.Where u can drag the para or sentence from the whole page n paste in empty layout.
In a way if u want to make a very short notes of any book,it is must(i made whole spectrum book into 90 pages pdf usng this app)
I satisfied with the above two apps.
Right now using onlyGood notes.
Alternative to Good notes is Notability (regarding this i have no first hand experience).