diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/AppManagerActivity.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/AppManagerActivity.java
index e2bca69e..969697f7 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/AppManagerActivity.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/AppManagerActivity.java
@@ -50,7 +50,6 @@ public class AppManagerActivity extends Activity {
         }
     };
     final List<GBDeviceApp> appList = new ArrayList<>();
-    private ListView appListView;
     private GBDeviceAppAdapter mGBDeviceAppAdapter;
     private GBDeviceApp selectedApp = null;
 
@@ -60,7 +59,7 @@ public class AppManagerActivity extends Activity {
         setContentView(R.layout.activity_appmanager);
         getActionBar().setDisplayHomeAsUpEnabled(true);
 
-        appListView = (ListView) findViewById(R.id.appListView);
+        ListView appListView = (ListView) findViewById(R.id.appListView);
         mGBDeviceAppAdapter = new GBDeviceAppAdapter(this, appList);
         appListView.setAdapter(this.mGBDeviceAppAdapter);
         registerForContextMenu(appListView);
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceCoordinator.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceCoordinator.java
index 9b118ef5..81c48a83 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceCoordinator.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceCoordinator.java
@@ -7,9 +7,9 @@ import nodomain.freeyourgadget.gadgetbridge.discovery.DeviceCandidate;
 public interface DeviceCoordinator {
     String EXTRA_DEVICE_MAC_ADDRESS = "nodomain.freeyourgadget.gadgetbridge.discovery.DeviceCandidate.EXTRA_MAC_ADDRESS";
 
-    public boolean supports(DeviceCandidate candidate);
-    public boolean supports(GBDevice device);
-    public DeviceType getDeviceType();
+    boolean supports(DeviceCandidate candidate);
+    boolean supports(GBDevice device);
+    DeviceType getDeviceType();
 
     Class<? extends Activity> getPairingActivity();
 }
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceHelper.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceHelper.java
index 7179cc17..b527f671 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceHelper.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceHelper.java
@@ -1,7 +1,5 @@
 package nodomain.freeyourgadget.gadgetbridge;
 
-import android.bluetooth.BluetoothClass;
-
 import java.util.ArrayList;
 import java.util.List;
 
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceSupport.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceSupport.java
index 433d37d7..a5932bc6 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceSupport.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/DeviceSupport.java
@@ -15,21 +15,20 @@ import android.content.Context;
  * via Bluetooth, Bluetooth LE, Wifi or something else.
  */
 public interface DeviceSupport extends EventHandler {
-    public void initialize(GBDevice gbDevice, BluetoothAdapter btAdapter, Context context);
+    void initialize(GBDevice gbDevice, BluetoothAdapter btAdapter, Context context);
 
-    public boolean isConnected();
+    boolean isConnected();
 
-    public boolean connect();
+    boolean connect();
 
-    public void dispose();
+    void dispose();
 
-    public GBDevice getDevice();
+    GBDevice getDevice();
 
-    public BluetoothAdapter getBluetoothAdapter();
+    BluetoothAdapter getBluetoothAdapter();
 
-    public Context getContext();
+    Context getContext();
+    boolean useAutoConnect();
 
-    public boolean useAutoConnect();
-
-    public void pair();
+    void pair();
 }
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/EventHandler.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/EventHandler.java
index 390b92bd..068ebd18 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/EventHandler.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/EventHandler.java
@@ -1,23 +1,23 @@
 package nodomain.freeyourgadget.gadgetbridge;
 
 public interface EventHandler {
-    public void onSMS(String from, String body);
+    void onSMS(String from, String body);
 
-    public void onEmail(String from, String subject, String body);
+    void onEmail(String from, String subject, String body);
 
-    public void onSetTime(long ts);
+    void onSetTime(long ts);
 
-    public void onSetCallState(String number, String name, GBCommand command);
+    void onSetCallState(String number, String name, GBCommand command);
 
-    public void onSetMusicInfo(String artist, String album, String track);
+    void onSetMusicInfo(String artist, String album, String track);
 
-    public void onFirmwareVersionReq();
+    void onFirmwareVersionReq();
 
-    public void onBatteryInfoReq();
+    void onBatteryInfoReq();
 
-    public void onAppInfoReq();
+    void onAppInfoReq();
 
-    public void onAppDelete(int id, int index);
+    void onAppDelete(int id, int index);
 
-    public void onPhoneVersion(byte os);
+    void onPhoneVersion(byte os);
 }
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBCallControlReceiver.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBCallControlReceiver.java
index 3dd29541..949f4d0d 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBCallControlReceiver.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBCallControlReceiver.java
@@ -39,8 +39,6 @@ public class GBCallControlReceiver extends BroadcastReceiver {
                 }
                 break;
             default:
-                return;
         }
-
     }
 }
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/SettingsActivity.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/SettingsActivity.java
index 9919ca28..3e3140b9 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/SettingsActivity.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/SettingsActivity.java
@@ -1,15 +1,8 @@
 package nodomain.freeyourgadget.gadgetbridge;
 
 import android.content.Intent;
-import android.media.audiofx.BassBoost;
 import android.os.Bundle;
-import android.preference.ListPreference;
 import android.preference.Preference;
-import android.preference.PreferenceActivity;
-import android.preference.PreferenceManager;
-import android.support.v4.app.NavUtils;
-import android.support.v4.content.LocalBroadcastManager;
-import android.view.MenuItem;
 
 import nodomain.freeyourgadget.gadgetbridge.activities.AbstractSettingsActivity;
 import nodomain.freeyourgadget.gadgetbridge.miband.MiBandPreferencesActivity;
@@ -25,7 +18,7 @@ public class SettingsActivity extends AbstractSettingsActivity {
     protected void onPostCreate(Bundle savedInstanceState) {
         super.onPostCreate(savedInstanceState);
 
-        Preference pref = (Preference) findPreference("notifications_generic");
+        Preference pref = findPreference("notifications_generic");
         pref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
             public boolean onPreferenceClick(Preference preference) {
                 Intent enableIntent = new Intent("android.settings.ACTION_NOTIFICATION_LISTENER_SETTINGS");
@@ -33,7 +26,7 @@ public class SettingsActivity extends AbstractSettingsActivity {
                 return true;
             }
         });
-        pref = (Preference) findPreference("pref_key_miband");
+        pref = findPreference("pref_key_miband");
         pref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
             public boolean onPreferenceClick(Preference preference) {
                 Intent enableIntent = new Intent(SettingsActivity.this, MiBandPreferencesActivity.class);
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AbstractSettingsActivity.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AbstractSettingsActivity.java
index c0975bf3..dc51417a 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AbstractSettingsActivity.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AbstractSettingsActivity.java
@@ -53,7 +53,7 @@ public class AbstractSettingsActivity extends PreferenceActivity {
                 preference.setSummary(stringValue);
             }
         }
-    };
+    }
 
     private static class ExtraSetSummaryOnChangeListener extends SimpleSetSummaryOnChangeListener {
         private Preference.OnPreferenceChangeListener delegate;
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AndroidPairingActivity.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AndroidPairingActivity.java
index 2fd7df98..284f6791 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AndroidPairingActivity.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AndroidPairingActivity.java
@@ -1,10 +1,7 @@
 package nodomain.freeyourgadget.gadgetbridge.activities;
 
 import android.app.Activity;
-import android.support.v7.app.ActionBarActivity;
 import android.os.Bundle;
-import android.view.Menu;
-import android.view.MenuItem;
 
 import nodomain.freeyourgadget.gadgetbridge.R;
 
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/adapter/DeviceCandidateAdapter.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/adapter/DeviceCandidateAdapter.java
index 92487de2..b98d683b 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/adapter/DeviceCandidateAdapter.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/adapter/DeviceCandidateAdapter.java
@@ -18,13 +18,11 @@ import nodomain.freeyourgadget.gadgetbridge.discovery.DeviceCandidate;
 public class DeviceCandidateAdapter extends ArrayAdapter<DeviceCandidate> {
 
     private final Context context;
-    private final List<DeviceCandidate> deviceCandidates;
 
     public DeviceCandidateAdapter(Context context, List<DeviceCandidate> deviceCandidates) {
         super(context, 0, deviceCandidates);
 
         this.context = context;
-        this.deviceCandidates = deviceCandidates;
     }
 
     @Override
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/adapter/GBDeviceAppAdapter.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/adapter/GBDeviceAppAdapter.java
index 20a18776..e26c2552 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/adapter/GBDeviceAppAdapter.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/adapter/GBDeviceAppAdapter.java
@@ -16,13 +16,11 @@ import nodomain.freeyourgadget.gadgetbridge.R;
 public class GBDeviceAppAdapter extends ArrayAdapter<GBDeviceApp> {
 
     private final Context context;
-    private final List<GBDeviceApp> appList;
 
     public GBDeviceAppAdapter(Context context, List<GBDeviceApp> appList) {
         super(context, 0, appList);
 
         this.context = context;
-        this.appList = appList;
     }
 
     @Override
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/btle/GattCallback.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/btle/GattCallback.java
index 35d6915f..da3951f7 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/btle/GattCallback.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/btle/GattCallback.java
@@ -33,13 +33,13 @@ public interface GattCallback {
      * @param newState
      * @see BluetoothGattCallback#onConnectionStateChange(BluetoothGatt, int, int)
      */
-    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState);
+    void onConnectionStateChange(BluetoothGatt gatt, int status, int newState);
 
     /**
      * @param gatt
      * @see BluetoothGattCallback#onServicesDiscovered(BluetoothGatt, int)
      */
-    public void onServicesDiscovered(BluetoothGatt gatt);
+    void onServicesDiscovered(BluetoothGatt gatt);
 
     /**
      * @param gatt
@@ -47,7 +47,7 @@ public interface GattCallback {
      * @param status
      * @see BluetoothGattCallback#onCharacteristicRead(BluetoothGatt, BluetoothGattCharacteristic, int)
      */
-    public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status);
+    void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status);
 
     /**
      * @param gatt
@@ -55,7 +55,7 @@ public interface GattCallback {
      * @param status
      * @see BluetoothGattCallback#onCharacteristicWrite(BluetoothGatt, BluetoothGattCharacteristic, int)
      */
-    public void onCharacteristicWrite(BluetoothGatt gatt,
+    void onCharacteristicWrite(BluetoothGatt gatt,
                                       BluetoothGattCharacteristic characteristic, int status);
 
     /**
@@ -63,7 +63,7 @@ public interface GattCallback {
      * @param characteristic
      * @see BluetoothGattCallback#onCharacteristicChanged(BluetoothGatt, BluetoothGattCharacteristic)
      */
-    public void onCharacteristicChanged(BluetoothGatt gatt,
+    void onCharacteristicChanged(BluetoothGatt gatt,
                                         BluetoothGattCharacteristic characteristic);
 
 //    /**
@@ -97,7 +97,7 @@ public interface GattCallback {
      * @param status
      * @see BluetoothGattCallback#onReadRemoteRssi(BluetoothGatt, int, int)
      */
-    public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status);
+    void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status);
 
 //    /**
 //     * @see BluetoothGattCallback#onMtuChanged(BluetoothGatt, int, int)
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/discovery/DiscoveryActivity.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/discovery/DiscoveryActivity.java
index 11e99287..40c72d8d 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/discovery/DiscoveryActivity.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/discovery/DiscoveryActivity.java
@@ -93,7 +93,6 @@ public class DiscoveryActivity extends Activity implements AdapterView.OnItemCli
     private ProgressBar progressView;
     private BluetoothAdapter adapter;
     private ArrayList<DeviceCandidate> deviceCandidates = new ArrayList<>();
-    private ListView deviceCandidatesView;
     private DeviceCandidateAdapter cadidateListAdapter;
     private Button startButton;
     private Scanning isScanning = Scanning.SCANNING_OFF;
@@ -122,7 +121,7 @@ public class DiscoveryActivity extends Activity implements AdapterView.OnItemCli
         progressView.setProgress(0);
         progressView.setIndeterminate(true);
         progressView.setVisibility(View.GONE);
-        deviceCandidatesView = (ListView) findViewById(R.id.discovery_deviceCandidatesView);
+        ListView deviceCandidatesView = (ListView) findViewById(R.id.discovery_deviceCandidatesView);
 
         cadidateListAdapter = new DeviceCandidateAdapter(this, deviceCandidates);
         deviceCandidatesView.setAdapter(cadidateListAdapter);
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandConst.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandConst.java
index 2005d322..ca5aa9c8 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandConst.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandConst.java
@@ -1,7 +1,5 @@
 package nodomain.freeyourgadget.gadgetbridge.miband;
 
-import nodomain.freeyourgadget.gadgetbridge.GB;
-
 public interface MiBandConst {
     String PREF_USER_ALIAS = "mi_user_alias";
     String PREF_USER_YEAR_OF_BIRTH = "mi_user_year_of_birth";
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandPreferencesActivity.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandPreferencesActivity.java
index dd6c5a14..a8243898 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandPreferencesActivity.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandPreferencesActivity.java
@@ -3,11 +3,9 @@ package nodomain.freeyourgadget.gadgetbridge.miband;
 import android.content.Intent;
 import android.os.Bundle;
 import android.preference.Preference;
-import android.preference.PreferenceActivity;
 import android.support.v4.content.LocalBroadcastManager;
 
 import nodomain.freeyourgadget.gadgetbridge.ControlCenter;
-import nodomain.freeyourgadget.gadgetbridge.GB;
 import nodomain.freeyourgadget.gadgetbridge.R;
 import nodomain.freeyourgadget.gadgetbridge.activities.AbstractSettingsActivity;
 
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandSupport.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandSupport.java
index ad3362df..a0ed2d62 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandSupport.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandSupport.java
@@ -279,8 +279,8 @@ public class MiBandSupport extends AbstractBTLEDeviceSupport {
             if (pairResult.length == 1) {
                 try {
                     byte b = pairResult[0];
-                    Integer intValue = Integer.valueOf(b);
-                    if (intValue.intValue() == 2) {
+                    Integer intValue = (int) b;
+                    if (intValue == 2) {
                         LOG.info("Successfully paired  MI device");
                         return;
                     }
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/UserInfo.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/UserInfo.java
index 6699fa72..65b77b2e 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/UserInfo.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/UserInfo.java
@@ -74,8 +74,7 @@ public class UserInfo {
             sequence[u] = normalizedAlias.getBytes()[u - 9];
 
         byte[] crcSequence = new byte[19];
-        for (int u = 0; u < crcSequence.length; u++)
-            crcSequence[u] = sequence[u];
+        System.arraycopy(sequence, 0, crcSequence, 0, crcSequence.length);
 
         sequence[19] = (byte) ((getCRC8(crcSequence) ^ Integer.parseInt(address.substring(address.length() - 2), 16)) & 0xff);
 
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/pebble/PBWReader.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/pebble/PBWReader.java
index 4eee3ee3..7f6d8d0d 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/pebble/PBWReader.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/pebble/PBWReader.java
@@ -52,7 +52,7 @@ public class PBWReader {
         this.uri = uri;
         cr = context.getContentResolver();
 
-        InputStream fin = null;
+        InputStream fin;
         try {
             fin = new BufferedInputStream(cr.openInputStream(uri));
 
@@ -153,7 +153,7 @@ public class PBWReader {
     }
 
     public ZipInputStream getInputStreamFile(String filename) {
-        InputStream fin = null;
+        InputStream fin;
         try {
             fin = new BufferedInputStream(cr.openInputStream(uri));
 
@@ -163,7 +163,7 @@ public class PBWReader {
         }
 
         ZipInputStream zis = new ZipInputStream(fin);
-        ZipEntry ze = null;
+        ZipEntry ze;
         try {
             while ((ze = zis.getNextEntry()) != null) {
                 if (ze.getName().equals(filename)) {