Music Memos by Apple - An app to capture your song ideas
JustNotepad.com - A free online notepad allows you to create any text or notes in your web browser.
Bandlab - Capture, nurture, and collaborate on song ideas in the cloud
TakeNote - A web-based note-taking app with GitHub sync and Markdown support.
DeepJ - AI-composed piano music in real time
PlicPad - Shareable notepad without urls