What are some alternatives?
When comparing FlowMapp and VisualSitemaps, you can also consider the following products
Really Good UX - A library of screenshots for UX inspiration
Sitemod - Modify any website in real-time. Share it with the world.
DYNO Mapper - Create Sitemaps with the DYNO Mapper Visual Sitemap Generator.
MockFlow SiteMap - Create beautiful sitemaps & UI flow
UX Recipe for iOS - Design checklist & estimation tool for your next UX project
Zen Flowchart - The simplest tool to create flowcharts