Open the MEGA app when a site link is clicked on the webview

I'm developing an app for my site and I want it when a certain user clicks on the download link, which in this case is in the mega, open the mega app automatically, just like it is done in chrome browsers and all others. Remember that it has to be functional for any MEGA link because there are several and they change. So it has to match everyone. I'm starting programming, and I've done a lot of research, but I have not found what I really wanted. Here's my main activity:

import android.app.Activity;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.widget.Toolbar;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.Toast;

public class MainActivity extends ActionBarActivity {

    private DrawerLayout mDrawerLayout;
    private ListView mDrawerList;
    String[] titles = {"Nigeria", "Ghana", "Senegal", "Togo"};
    private CharSequence mTitle;
    private CharSequence mDrawerTitle;
    private ActionBarDrawerToggle mDrawerToggle;
    private Toolbar topToolBar;
    private WebView webView;
    Activity activity = this;
    private ProgressBar progress;
    private WebView webview;
    private static final String TAG = "Main";
    private View view;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        webView = (WebView) findViewById(R.id.website);
        webView.getSettings().setLoadWithOverviewMode(true);
        webView.getSettings().setUseWideViewPort(true);

        webView.getSettings().setSupportZoom(true);
        webView.getSettings().setBuiltInZoomControls(true);
        webView.getSettings().setDisplayZoomControls(false);

        webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
        webView.setScrollbarFadingEnabled(false);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.loadUrl("http://meusite");

        webView.setWebViewClient(new WebViewClient() {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                webView.loadUrl(url);
                return false;
            }
        });

        progress = (ProgressBar) findViewById(R.id.progressBar);
        progress.setMax(100);

        mTitle = mDrawerTitle = getTitle();

        topToolBar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(topToolBar);

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (ListView) findViewById(R.id.left_drawer);

        mDrawerToggle = new ActionBarDrawerToggle(MainActivity.this, mDrawerLayout, R.string.drawer_open, R.string.drawer_close) {

            /** Called when a drawer has settled in a completely closed state. */
            public void onDrawerClosed(View view) {
                super.onDrawerClosed(view);
                getSupportActionBar().setTitle(mTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }

            /** Called when a drawer has settled in a completely open state. */
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                getSupportActionBar().setTitle(mDrawerTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }
        };

        // Set the drawer toggle as the DrawerListener
        mDrawerLayout.setDrawerListener(mDrawerToggle);
        mDrawerToggle.setDrawerIndicatorEnabled(true);

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);

        mDrawerList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                // make Toast when click
                Toast.makeText(getApplicationContext(), "Position " + position, Toast.LENGTH_LONG).show();
                selectItemFragment(position);
            }
        });
    }

    private void selectItemFragment(int position) {

        Fragment fragment = null;
        FragmentManager fragmentManager = getSupportFragmentManager();
        switch (position) {
            default:
            case 0:
                fragment = new DefaultFragment();
                break;
            case 1:
                fragment = new DefaultFragment();
                break;
            case 2:
                fragment = new DefaultFragment();
                break;
            case 3:
                fragment=new DefaultFragment();
                break;
        }
        fragmentManager.beginTransaction().replace(R.id.main_fragment_container, fragment).commit();

        mDrawerList.setItemChecked(position, true);
        setTitle(titles[position]);
        mDrawerLayout.closeDrawer(mDrawerList);
    }

    @Override
    public void setTitle(CharSequence title) {
        mTitle = title;
        getSupportActionBar().setTitle(mTitle);
    }

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        // Sync the toggle state after onRestoreInstanceState has occurred.
        mDrawerToggle.syncState();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        mDrawerToggle.onConfigurationChanged(newConfig);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // If the nav drawer is open, hide action items related to the content view
        boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
        return super.onPrepareOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }
        if (mDrawerToggle.onOptionsItemSelected(item)) {
            return true;
        }

        return super.onOptionsItemSelected(item);

    }

    private class MyWebViewClient extends WebChromeClient {
        @Override
        public void onProgressChanged(WebView view, int newProgress) {
            MainActivity.this.setValue(newProgress);
            super.onProgressChanged(view, newProgress);
        }
    }
    public void setValue(int progress) {
        this.progress.setProgress(progress);

}

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (event.getAction() == KeyEvent.ACTION_DOWN) {
            switch (keyCode) {
                case KeyEvent.KEYCODE_BACK:
                    if (webView.canGoBack()) {
                        webView.goBack();
                    } else {
                        finish();
                    }
                    return true;
            }

        }
        return super.onKeyDown(keyCode, event);
    }
}