Building apps that receive data from dumbphones...

Hi. New here but with some coding experience. I'm currently living in rural Guinea and I have been shocked by the reach of telecom services including dumbphone compatible applications like mobile money transfer apps and SIM card services that use USSD codes.

If anyone here is familiar with the Orange Money service, I was looking for info on what goes into developing a desktop app that communicates with phones via text message or USSD code and can load that info into a SQL database or something like that. Anyone got development experience with similar apps that could point me in the right direction to get started?