The Nota text editor features a simple interface by default.
Gnome Text Editor
A simple text editor.
Pulsar
A Community-led Hyper-Hackable Text Editor.
Torium Reader
Thorium Reader is an easy to use EPUB reading application.
Rerehua Linwood
Powerful, minimalistic, cross-platform, opensource note-taking app.
PDF matua
A simple lightweight PDF viewer.
Papakiore
Mousepad is a simple text editor for Xfce .
He kikokore
sleek is a todo app based on todo.txt, free and open-source.
Dupeguru
dupeGuru is a cross-platform (Linux, OS X, Windows) GUI tool to find duplicate files in a system.
Corepad
A document editor for C Suite.