API Connector by Mixed Analytics - Connect any API to Google Sheets.
Sheety - Turn any Google sheet into an API instantly, for free. Power websites, apps, or whatever you like, all from a spreadsheet. Changes to your spreadsheet update your API in realtime. Neat
Hoss - Track and manage third-party APIs
SheetBest - Turn a Google SpreadSheet into a JSON Database API
API to bot - Convert your API to Alexa skill or Google Home app in 5 mins
Dashblock - Turn any website into an API