Startup School - How to start a startup, by Y Combinator
SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters
Hyper Founder Program - An 8-week founder program inspired by Product Hunt
DeskAlerts - Send alerts to any corporate device: PCs, phones, tablets, etc.
Indie Hackers - Connect with fellow entrepreneurs, developers, and bootstrappers who are sharing the strategies and revenue numbers behind their companies.
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.