Get elapsed time from the first time user launched the app using SharedPreferences and Joda-Time

secondsSinceLastLaunch.java

long lastLaunchedDateMillis = VITPreferencesUtils.getLongGeneric(PuzzleApp.getInstance(), "first_launch_date", -1);

DateTime current = new DateTime();
DateTime lastLaunchedDate = new DateTime(lastLaunchedDateMillis);
if (lastLaunchedDateMillis != -1) {
    int secsElapsed = Seconds.secondsBetween(lastLaunchedDate, current).getSeconds();
    Log.e("VI PRINT", "HomeActivity.onCreate " + "secsElapsed:" + secsElapsed);
} else {
    VITPreferencesUtils.saveLongGeneric(PuzzleApp.getInstance(), "first_launch_date", current.getMillis());
}