CrocodileNote is described as 'Take simple text notes. You can put them into folders to create your own quick, easy and robust file structure'. There are more than 100 alternatives to CrocodileNote for a variety of platforms, including Windows, Mac, Online / Web-based, Android and iPhone. The best alternative is Joplin, which is both free and Open Source. Other great apps like CrocodileNote are Standard Notes (Freemium, Open Source), Google Keep (Free), Microsoft OneNote (Freemium) and Evernote (Freemium).
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.