Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Snappa - The perfect graphic design tool for digital marketers.
Sketch - Professional digital design for Mac.
Canva - Canva is a graphic-design platform with a drag-and-drop interface to create print or visual content while providing templates, images, and fonts. Canva makes graphic design more straightforward and accessible regardless of skill level.
Adobe Illustrator - Adobe Illustrator is a vector graphics editor.
Artboard Studio - Online graphic design app mainly focused on product mockups.