What if we only want the first three elements of an Observable sequence, emit them, and then let the Observable complete? The take() function gets an N integer as a parameter, emits only the N first elements from the original sequence, and then it completes:

private void loadList(List<AppInfo> apps) {
    mRecyclerView.setVisibility(View.VISIBLE);

    Observable.from(apps)
            .take(3)
            .subscribe(new Observer<AppInfo>() {
                @Override
                public void onCompleted() {
                    mSwipeRefreshLayout.setRefreshing(false);
                }

                @Override
                public void onError(Throwable e) {
                    Toast.makeText(getActivity(), "Something went  south!", Toast.LENGTH_SHORT).show();
                    mSwipeRefreshLayout.setRefreshing(false);
                }

                @Override
                public void onNext(AppInfo appInfo) {
                    mAddedApps.add(appInfo);
                    mAdapter.addApplication(mAddedApps.size() - 1,  appInfo);
                }
            });
}

The next figure shows an Observable sequence emitting numbers. We will apply a take(2) function to this sequence, and then we can create a new sequence emitting just the first and second item of the Observable source.

If we want the last N elements, we just use the takeLast() function:

Observable.from(apps)
        .takeLast(3)
        .subscribe(…);

As trivial as it sounds, it's important to note that the takeLast() function applies only to the sequence that completes due to its nature of working with a finite amount of emitted items.

The next figure shows how we can create a sequence emitting only the last element from a Observable source:

The next figure shows what happens when we apply take() and takeLast() to our installed applications list example: