TopNotes is described as 'powerful app for handwriting and organizing notes, sketches, diagrams, illusions and drawings. It is the easiest-to-use and going to be the best-selling handwriting app for iPad' and is an app in the Office & Productivity category. There are more than 50 alternatives to TopNotes for a variety of platforms, including Windows, Android, iPhone, iPad and Online / Web-based. The best alternative is Joplin, which is both free and Open Source. Other great apps like TopNotes are Standard Notes (Freemium, Open Source), Evernote (Freemium), CherryTree (Free, Open Source) and Cryptee (Freemium, Open Source).
Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, can be copied, tagged and modified either from the applications directly or from your own text editor.
Colorful & powerful sticky notes app for Windows & Phones. Set reminder alarms, attach them to any website or document, organize them using folders/tags, sync sticky notes between devices & send notes across LAN or to any contact across the globe.