IOTAPAY is an open source project driven by Acyclic Labs.
The balance check feature is supported by IOTAPAY nodejs lib.
We also have the IOTAPAY python lib, in case your project uses python.
If you need more complex integration, feel free to reach out to us at firstname.lastname@example.org.
If you are facing any issues or just want to say hi, we implore you to reach out to us regarding the same at any point.
Work best in Google Chrome browser.