Android Phone

Android phone is fine environment to develop new features like distributes database, meaning that there is no server's for database, but database is located in every phone running this app. This is done with networking and accessibility. Every hone can be access with IPv6. Well, in practice not in every moment, but  reliable enough. Still we need servers that share connections and data to those phones that are not accessible at this moment. Still server-structure is light.

Developing in Android

Developing in Android is sometimes very confusing. Quality of documenting and recommended structure of app varies. New features are often badly documented and structure of app is not well managed.

User Interface

Recommended User Interface is fragment based. You add new app feature to a new fragment and add logic how user travels to a fragment with new feature. This works fine when app does nothing. Problems come, when you add real behavior implementing, the logic how data is handled.

Data handling

Data handling is traditionally done with Activity-classes, which is also UI-class.  Acctivity classes can communicate with each others. Fracgent-tructure, the UI-logic need one Activity-class to work. Oher Acrivity classes are for fuctionality. This dounble role of Activity-class makes trouble nowdays, bacause the is a lot of data logic - even if this data logic can use also UI - that is libraries, meabing that some other has already implemented functionality - normal way to implement apps, it is no mean if every app in implemeted from the start, we need libraries and the is lot of libraries functionality done by Google to the Android.

This double role of Activity makes trouble, when UI generations argue with different library versions. We coders often need only the data functionality, but that library has dependencies to UI, butnot to our UI. nut UJI cöasses and what worse, to UI settings, styles used in the app.