KiddoPaint - MS Paint in your browser (with emojis 💃😽🎨)
Icons8 Background Remover - Quickly remove the background from any photo
JS Canvas - Classic MS-Paint redone as a web application
ClippingMagic.com - Remove image backgrounds online. Make backgrounds transparent, white, etc. Edit, crop, rotate, fix colors, add shadows, all you need for great photos!
JS Paint - JSPaint is a web-based Microsoft Paint remake
Bg Eraser - Background Eraser on Mac and Windows.