Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Louvre Museum Online - Explore the entirety of the Louvre's collection for free
Standard Notes - A safe place for your notes, thoughts, and life's work
The Met - Official app of The Metropolitan Museum of Art
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.
Sketchfab for Museums - Browse thousands of cultural artifacts in 3D and VR