Noteshelf is described as 'Take beautiful handwritten notes or annotate PDFs on your iPad, and now even on your iPhone' and is an app in the Audio & Music category. There are more than 100 alternatives to Noteshelf for a variety of platforms, including Windows, iPhone, iPad, Android and Mac. The best alternative is Joplin, which is both free and Open Source. Other great apps like Noteshelf are Standard Notes (Freemium, Open Source), Microsoft OneNote (Freemium), CherryTree (Free, Open Source) and NoteLedge - Creative Notebook (Paid).
WizNote is a Note software, which is especially designed for Internet users and mobile Internet users. WizNote focuses more on notes of rapid collection, management, reading and sharing. WizNote is smaller, more stable, and more suitable for computers, phones and mobile devices.
NixNote, formerly Nevernote, is an open source client for Evernote . It is written in Java so it will also run on Windows & OS-X, but the primary focus has been to try and get a usable environment for Linux.