sharedpreferences

I'm building an app to run tasks every hour, and I want to show Countdown. But when I exit the app, upon coming back, the count restarts. I need that when I return to the app, the count is continuing. Can anyone help me ?

How do I save and retrieve information in an Android Prefence file. Example String a = "stack overflow" int b = 32; boolean c = true;

I am studying persistence for android, however I am having a hard time understanding the levels of persistence they do in app ... ther two if they are "the same function"? Can I share these preferences with each other? Does Web service fit a server type?

I have apps a, b, c and D and I need to share data from those apps, for a specific app (E) (basically the login data, ... all apps in the application and is unfeasible. Wanted to know another way to share this data and do this automatic login.