A very simple sticky list header helper.

activity_sticky_list.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <ListView
        android:id="@+id/list_view"
        style="@style/list_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="6dp"
        android:paddingRight="4dp"
        android:scrollbarStyle="outsideOverlay"/>

    <FrameLayout
        android:id="@+id/fl_sticky_header_holder"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:background="@null"/>
</FrameLayout>

StickyListActivity.java

public class StickyListActivity extends Activity {

  @InjectView(R.id.fl_sticky_header_holder) FrameLayout stickyHeaderHolder;
  @InjectView(R.id.list_view) ListView listView;
  
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.setContentView(R.layout.activity_sticky_list);
    Butterknife.inject(this);
    
    StickyHeaderHelper<String> stickyHeaderHelper = new StickyHeaderHelper<String>(
                this.listAdapter, this.stickyHeaderHolder, this.listView);
    this.listView.setOnScrollListener(stickyHeaderHelper);
    this.listAdapter.registerDataSetObserver(stickyHeaderHelper);
  }
}

StickyListHelper.java

import android.database.DataSetObserver;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;

/**
 * @author jaynewstrom
 * Created on 1/28/14.
 */
public class StickyHeaderHelper<S> extends DataSetObserver implements OnScrollListener {

    private final StickyHeaderAdapter<S> adapter;
    private final ViewGroup stickyHeaderHolder;
    private final AbsListView listView;

    private S previousSection;
    private int previousFirstVisibleItem;

    public StickyHeaderHelper(StickyHeaderAdapter<S> adapter, ViewGroup stickyHeaderHolder, AbsListView listView) {
        this.adapter = adapter;
        this.stickyHeaderHolder = stickyHeaderHolder;
        this.listView = listView;
        this.reset();
    }

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {}

    @Override
    public void onScroll(AbsListView absListView, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
        this.updateHeaderView(firstVisibleItem);
    }

    private void updateHeaderView(int firstVisibleItem) {
        S section = this.adapter.getSectionForIndex(firstVisibleItem);

        if (section != null) {
            if (this.previousFirstVisibleItem != firstVisibleItem && firstVisibleItem >= 0) {
                if (this.previousSection == null || !this.previousSection.equals(section)) {
                    View view = this.adapter.getViewForSection(section);
                    this.stickyHeaderHolder.removeAllViews();
                    this.stickyHeaderHolder.addView(view);
                    this.previousSection = section;
                }

                this.previousFirstVisibleItem = firstVisibleItem;
            }

            if (firstVisibleItem <= this.listView.getCount()) {
                S nextSection = this.adapter.getSectionForIndex(firstVisibleItem + 1);
                View header = this.stickyHeaderHolder.getChildAt(0);
                if (header != null) {
                    View firstItem = this.listView.getChildAt(1);
                    int firstItemTop = firstItem == null ? 0 : firstItem.getTop();

                    if (section.equals(nextSection)) {
                        header.setTranslationY(0);
                    } else {
                        int transY = Math.min(0, firstItemTop - header.getMeasuredHeight());
                        header.setTranslationY(transY);
                    }

                    View zeroItem = this.listView.getChildAt(0);
                    if (firstVisibleItem == 0 && zeroItem != null && zeroItem.getTop() == 0) {
                        this.previousSection = null;
                        this.previousFirstVisibleItem = -1;
                        this.stickyHeaderHolder.removeAllViews();
                    }
                }
            }
        }
    }

    private void reset() {
        this.previousSection = null;
        this.previousFirstVisibleItem = -1;
        this.stickyHeaderHolder.removeAllViews();

        if (this.listView.getCount() > 0) {
            this.listView.setSelection(0);
            this.updateHeaderView(0);
        }
    }

    @Override
    public void onChanged() {
        this.reset();
    }

    @Override
    public void onInvalidated() {
        this.reset();
    }

    public interface StickyHeaderAdapter<S> {
        public S getSectionForIndex(int index);
        public View getViewForSection(S section);
    }
}