I am working on a project where I am utilizing multiple Raspberry Pi's and ESP32's to create an electronic challenge game for my friends. The game involves competing in challenges to earn points. I am looking to connect these devices together to enable event triggering and score recording, with all information accessible from an app and to the devices.
I have 4g cellular connection to all the devices.
My question is, what is the most suitable communication method to connect these devices together with an app? I am considering options like MQTT, SQL, TCP/IP, or other alternatives. Additionally, I am seeking recommendations for hobbyist-friendly hosting solutions that support the chosen communication method and do not require local hosting.
Any insights or recommendations on the best approach and suitable hosting solutions would be greatly appreciated. Thank you!