Notability, CollaNote, Flexcil, Samsung Notes, MarginNote, iAnnotate, Penultimate, HandWrite Pro, Touchnotes, INKredible, Inkflow Visual Notebook, LectureNotes, PDF Professional, TopNotes, WritePad, Knowte, Saber: Handwritten Notes, Umbrella Note, pdf-notes, ePapyrus PDF-Pro, Agenda Mahala, Notespark, POKATreader, MakerX are some alternatives to Noteshelf.