FiiNote - FiiNote is the most convenient note app for android.

Nebulous Notes - Nebulous Notes is a powerful, yet simple, text editor for note-takers, writers, and coders.

jEdit - jEdit is a mature programmer's text editor with a large collection of plugins

Coastline - Simple minimalist text editor. Create, open, edit and save plain text files.

Google Keep - Capture notes, share them with others, and access them from your computer, phone or tablet. Free with a Google account.

Joplin - 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, tagged and modified either from the applications directly or from your own text editor.