Twilio SMS API: https://www.twilio.com/docs/api/rest/message
- Create custom alerts by combining this with any other API
- Scrape data from websites and send alerts
- Implement games like Werewolf/Mafia in text
Youtube Search API: https://developers.google.com/youtube/v3/docs/search/list
- Combine with other APIs to get links to Youtube videos
Facebook Graph API: https://developers.facebook.com/docs/graph-api
- You can read posts on any group or page you're in
- You can also post to any group or page
- Automatically post alerts to a Facebook group
- Automatically upload pictures/videos at a specific time every day
- Repost content from other groups onto your group
Sendgrid Email API: https://sendgrid.com/docs/API_Reference/Web_API_v3/Mail/index.html
- Similar to Twilio, but for emails instead, and hence free
- Create mailing lists or email notifications