Checkbot - Checkbot will boost the SEO, speed and security of your site by checking you're following 50+ web best practices. Browser extension with free and paid plans.
XML-Sitemaps.com - Free Online Google Sitemap Generator.
Fast Link Checker - An advanced tool to find broken links on web sites.
MySitemapGenerator - Online XML generator tool for SEO and eCommerce. Creates Sitemaps, shopping ads feeds, RSS, and podcast feeds.
Pulno - SEO Audit and Website Analysis. Pull up your SEO.
DYNO Mapper - Create Sitemaps with the DYNO Mapper Visual Sitemap Generator.