WordPress backend and API

I have a calculator mobile app and currently all the values are hard coded and this is causing issues every time the values change I need to update the mobile app and republish.

I want to move the values to a server and want the mobile app to get the values from the server. I have few categories and each category has slightly different parameters/values. Wondering whether I can use WordPress to build the backend to manage the values? is there a plugin or framework I can use to do this or will have to build a custom plugin. Would like an API or at least a feed the mobile app can use to get the values.