YouClap - Challenge and be challenged by friends and brands.
SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters
Spinnner - Challenge your friends to a spin-off (literally)
DeskAlerts - Send alerts to any corporate device: PCs, phones, tablets, etc.
UXTesting - Discover how your mobile users feel
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.