Majestic - Majestic - Link intelligence tools for SEO and Internet PR and Marketing. Site Explorer shows inbound link and site summary data.
FlowMapp - FlowMapp is a UX planning tool for creating visual sitemaps and user flow.
Moz - Backed by industry-leading data and the largest community of SEOs on the planet, Moz builds tools that make inbound marketing easy.
A1 Sitemap Generator - A1 Sitemap Generator has been in active development and sold since 2005.
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
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.