Be sure to check out the 2 hours worth of video as well as the references!. The webinar introduces API calls and compares / contrasts them to a browser call / Web scraping. It also covers a ton about pluses & minuses between the two.
I use Fiddler to help monitor network traffic. Check out my videos on Fiddler for monitoring Network Traffic. They can really help understand what is being sent from the Apps / Website so you know what you need to replicate.
Here is a link to my AutoHotkey API Syntax writer. It can save you significant amount of time writing your AutoHotkey Code!

In most of the below examples I use the below function I wrote to parse the parameters. Please make sure you add it to your scripts!
Example API Calls
- FullContact- Company & Person lookup
- Clearbit- Contact Search
- Data24-7- Return email address for a mobile phone number
- reddit- Return top 20 AHK posts from Reddit; avoid oAuth2 by leveraging browser cookies!
- SmartSheet- Extract JSON as well as binary data (CSV)
- OpenWeatherMap- Grab the current & forecaster weather conditions in XML or JSON
- Yahoo Query- Play with the highly-flexible Yahoo queries!
- Yelp- Work through oAuth1 & oAuth2 to connect to the Yelp API
- Zillow- Extract some great Real estate data from the Zillow API
- Zoom- Vendors often offer APIs to access your data. I demo connecting to Zoom.us here.
- Google Maps– I work through 4 APIs: Directions, Timezone, Places, and GeoLocation
- RingCentral- API Calls (Automate Texting, calling, etc.)