I need some help with a commerce app that I am working on. The app the I am talking about is an app that saves all the debts you have with your friends. For example if you owe 20 dollars to one of your friends it will save it and remind it to you but then if he gives you back 10 the app needs to know that he still needs to give you 10 more. It is like the money pie bot in telegram.
To do this I created a database in Firebase to save all information necessary. But I don´t know how to interact with the database to take those numbers and interact with them, adding and subtracting. Also I need to create an additional list that just shows the money you owe and the money they owe you.
If someone wants to help I can give him my Discord or Skype.