app to web communication

I have 20+ years of experience in Java/j2ee. I can help you to clarify your doubts and setup the server. If you want me to code for the whole project that we discuss later.

I could create serevr that will have rest api. The application will have to call to the rest api every some seconds, and update the number of coins. I could give you the rest api in 3-4 days, with working server. Even this solution budget should be higher than 30$. Please discuss it. Second option is to send message that the application will listen to this message. The part of the application will be more complex.

I have enough knowledge for communication between website and app. I am having previous experience on this.

we have multiple members so we can plan early release as well.