Giveaway by buttons, by comments, among all subscribers, the contest "subscribe a friend". Checking subscriptions. Statistics and uploading results to Excel.
Karmabot for Telegram - Free bot for tracking performance in chats
Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting
HiStaff - Make your staff and workspace happy
Monkey Test It - Primate powered algorithms that scan your site for common bugs and SEO mistakes.
iCliniq on Telegram - telegram bot that will get answers from real doctors
NIXStats - SaaS monitoring tool for window/linux servers and websites. Think up-time robot but with more features.