I find there's a problem in the FirstExampleFragment class

[zondaOf2012]

 private void refreshTheList() {
    getApps().toSortedList().subscribe ... ...
 }

should change to

 private void refreshTheList() {
    getApps().toSortedList().subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread()).subscribe ... ...
 }