public class MainActivity extends Activity implements OnClickListener{

    private final static String ODESK_CONSUMER_KEY = "17....07c321dc0dc628026d03c0873d";
    private final static String ODESK_CONSUMER_SECRET = "dc9....81fab724";
    private final static String OAUTH_CALLBACK_SCHEME = "x-oauthflow";
    Button login;
    public OAuthClient client;
    SharedPreferences prefs;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
        initUI();
        buildEvents();
    }

    //It is used to build the events
    private void buildEvents()
    {
        login.setOnClickListener(this);
    }

    //This function is used to initialize the variables
    private void initUI()
    {
        login = (Button)findViewById(R.id.login);
    }

    @Override
    public void onClick(View v)
    {
    switch (v.getId())
    {
    case R.id.login:
        getAccessToken();
        break;
    }
    }

    private void getAccessToken()
    {
        client = null;
        Properties props = new Properties();
        props.setProperty("consumerKey", ODESK_CONSUMER_KEY);
        props.setProperty("consumerSecret", ODESK_CONSUMER_SECRET);
        Config config = new Config(props);
        client = new OAuthClient(config);
        new ODeskAuthorizeTask().execute();
    }


    class ODeskAuthorizeTask extends AsyncTask<Void, Void, String> {

        private Exception exception;

        @Override
        protected String doInBackground(Void... params) {
            String authzUrl = client.getAuthorizationUrl();
            startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(authzUrl)));

            return authzUrl;
        }

        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);
            if (result != null) {
               Toast.makeText(MainActivity.this, result, Toast.LENGTH_LONG).show();
            }
        }
    }
}

<activity android:name="com.roopasoft.odeskmobile.MainActivity" >
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />

                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />

                <data
                    android:host="@string/app_name"
                    android:scheme="x-oauthflow" />
            </intent-filter>
        </activity>