Zen Flowchart - The simplest tool to create flowcharts
FlowMapp - FlowMapp is a UX planning tool for creating visual sitemaps and user flow.
Octopus.do - Build your website structure in real-time and rapidly share it to collaborate with your team or clients. Start prototyping websites or apps instantly.
Scheme Flowcharts - A huge pack of layouts for UX prototyping
DYNO Mapper - Create Sitemaps with the DYNO Mapper Visual Sitemap Generator.
Platforma Flowcharts - Collection of cards for website and app prototyping