HypeStat - HypeStat is free statistics and analytics service, where you can find information about every website.
SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters
Site Rank Data - View historical rank information of websites via time series charts.
DeskAlerts - Send alerts to any corporate device: PCs, phones, tablets, etc.
Q-Stats - Get free marketing insights for every question on Quora.
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.