OpenGraph.xyz - Check how search engines and social medias such as Google, Facebook, Twitter display your website
ImageKit.io - Instant multi-platform image optimization
MetaTagsTool.com - Meta Tag Analyzer, Simulator, & Generator
Promo.com - Every promotion starts with Promo.com.
Majestic - Majestic - Link intelligence tools for SEO and Internet PR and Marketing. Site Explorer shows inbound link and site summary data.
Assetizr - A super fast image resizing tool