App service for fetching best performing posts and generating content ideas

we are looking to develop an Application service that allows a user to find the best performing posts on social media platforms like "linkedin and twitter" and generate content ideas on top of it using AI.

Example:


For Linkedin
https://taplio.com/product/linkedin-post-inspiration


For Twitter
https://tweethunter.io/thread-finder
https://www.tweetlify.co/#viral


We are looking for free APIs and ways to develop this service.