Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
FlowMapp - FlowMapp is a UX planning tool for creating visual sitemaps and user flow.
UptimeRobot - Free Website Uptime Monitoring
A1 Sitemap Generator - A1 Sitemap Generator has been in active development and sold since 2005.
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
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.