What device can’t connect? Is it an Android phone?

This doesn’t make any sense. API requests are not proprietary.

Graph89 was awesome. It emulated a TI-89. The interface was old, but the functionality was unmatched. Unfortunately it has not been updated to work with the new phone CPU architectures. If you are running an older phone I highly recommend trying it.

Source?

Thanks for laying this out. You persuaded me.