A free graphics editor used to create vector graphics easily and intuitively. Vectr is available online for can be downloaded for Mac, Windows or Linux for offline use. It offers all the typical features and tools you'd expect making it a great free option for designing iOS apps. Everything created in Vectr is available online for real-time collaboration. Others can watch you create and edit designs live, whether you’re in the web app or desktop version. Vectr has just left beta, and the developers have an open roadmap with more great features coming soon.