If you’re thinking about building an app and don’t have time to start from scratch, you’re in luck. With all the advancements made in developer tools over the last two decades, especially application programming interfaces (APIs), building an app on your own has never been easier. APIs are the set of commands, functions, protocols, and objects that allow developers to create software more easily.

Here are 4 incredibly useful and affordable APIs you can start using to quickly and easily build impressively functional apps!

1. Register Users with Okta

The Okta API allows developers to quickly and easily build a custom end-to-end log-in experience for their applications. It provides you with all the tools needed to “

2. Harness the Power of Visual Recognition with Clarifai

Our API gives developers access to the most robust visual recognition AI in the market. With over 11,000+ concepts in our General model in 23 different languages (and 13 domain-specific models in total), whether you have 1 image or billions, our API can recognize your visual content.

Once you get your free API key, you can start sending your visual inputs to the service to start getting predictions. Need to recognize something specific? With our interface, developers can build a custom model and train it to understand and recognize your particular concepts.

3. Text Your Users with Twilio

Twilio’s Programmable SMS API allows developers to add messaging capabilities to their apps. With their software, developers can send and receive texts, track their delivery status and even manage your message history. Check out how our Senior Developer Evangelist, Skip Everling,integrated Twilio with a custom model that was built on our API.

Additionally, Twilio has a Programmable Chat API that allows developers to add chat features to their apps, “without building or scaling a real-time chat backend.” Chat has all the necessary APIs and features to integrate with your business logic to ensure you are in control.

4. Get Paid with Stripe

Stripe’s APIs allow developers to quickly integrate the payment and billing functionalities of Stripe into their apps for as little as 2.9% + 30 cents per credit card charge. These APIs offer a secure platform from which developers can readily accept and manage payments from users, even on behalf of third parties. With their Payment API, developers will not have to store sensitive card information on their servers. The app lets them collects and validate card information, then tokenizes this information, so it stays private. With their Billing API, developers can generate invoices for their customers before automatically working to collect the required payments.

Whether you use them on their own or integrate them with one another, with the above APIs, you can quickly and easily build the next big app for the world!