If you are looking to build something valuable and useful to your users or wanna fuel up your projects then google APIs are super useful and reliable services for any company. You can easily get started with there services because there has simple and easy documentation.
Google Maps API
Create/customize digital maps based on Google Maps data
Google Earth Engine
A cloud-based platform for planetary-scale environmental data analysis
Display, create and modify Google calendar events
Google Play Developer API
The Google Play Developer API is a REST-based web service that allows you to perform publishing and app-management tasks. You can use this API to integrate your publishing operations with your release-management process.
Collect, configure, and analyze your data to reach the right audience
Add YouTube functionality to your sites and apps.
Flexible, RESTful access to the user's inbox
With ML Kit's text recognition APIs, you can recognize text in any Latin-based language
With ML Kit's image labeling APIs, you can recognize entities in an image without having to provide any additional contextual metadata, using either an on-device API or a cloud-based API.
Face Detection with Firebase
With ML Kit's face detection API, you can detect faces in an image, identify key facial features, and get the contours of detected faces.
Barcode Scanning With Firebase
With ML Kit's barcode scanning API, you can read data encoded using most standard barcode formats.
Google Cloud Natural
Natural language understanding technologies to developers, including sentiment, entity, and syntax analysis