These are demos of applying MobX and MobX state tree in a UI5 app - originally accompanying a talk from UI5CON 2019 "Structured UI5 state management with MobX state tree".
Demo 1 shows a basic application that uses a JSON model.
Demo 2 shows the same application, but instead uses MobX under the hood.
Demo 3 is once again the same application, but now using MobX state tree.
Demo 4 adds a history slider to the application.