diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index e1ff0f4..0c032c2 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -4,8 +4,7 @@
 
     <uses-permission android:name="android.permission.RECORD_AUDIO"/>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
-    <!--全局异常检测，需添加-->
-    <!--android:name=".application.MyApplication"-->
+
     <application
         android:name=".application.MyApplication"
         android:allowBackup="true"
@@ -13,13 +12,21 @@
         android:label="@string/app_name"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
-        <activity android:name="com.jiangdg.usbcamera.view.USBCameraActivity">
+        <activity android:name="com.jiangdg.usbcamera.view.SplashActivity"
+            android:screenOrientation="portrait">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
+        <activity android:name=".view.USBCameraActivity"
+            android:screenOrientation="portrait">
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW"/>
+            </intent-filter>
+        </activity>
     </application>
 
 </manifest>
\ No newline at end of file
diff --git a/app/src/main/java/com/jiangdg/usbcamera/application/MyApplication.java b/app/src/main/java/com/jiangdg/usbcamera/application/MyApplication.java
index 768242c..e79041a 100644
--- a/app/src/main/java/com/jiangdg/usbcamera/application/MyApplication.java
+++ b/app/src/main/java/com/jiangdg/usbcamera/application/MyApplication.java
@@ -2,15 +2,18 @@ package com.jiangdg.usbcamera.application;
 
 import android.app.Application;
 
+import com.jiangdg.usbcamera.UVCCameraHelper;
 import com.jiangdg.usbcamera.utils.CrashHandler;
 
-/**全局类
+/**application class
  *
  * Created by jianddongguo on 2017/7/20.
  */
 
 public class MyApplication extends Application {
     private CrashHandler mCrashHandler;
+    // File Directory in sd card
+    public static final String DIRECTORY_NAME = "UVCCamera";
 
     @Override
     public void onCreate() {
diff --git a/app/src/main/java/com/jiangdg/usbcamera/utils/CrashHandler.java b/app/src/main/java/com/jiangdg/usbcamera/utils/CrashHandler.java
index 1165523..5bef590 100644
--- a/app/src/main/java/com/jiangdg/usbcamera/utils/CrashHandler.java
+++ b/app/src/main/java/com/jiangdg/usbcamera/utils/CrashHandler.java
@@ -9,6 +9,9 @@ import android.os.Environment;
 import android.os.Looper;
 import android.widget.Toast;
 
+import com.jiangdg.usbcamera.UVCCameraHelper;
+import com.jiangdg.usbcamera.application.MyApplication;
+
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
@@ -98,8 +101,11 @@ public class CrashHandler implements UncaughtExceptionHandler {
 			public void run() {
 				Looper.prepare();
 				Toast.makeText(mContext.getApplicationContext(),
-						"程序异常退出，即将重启...", Toast.LENGTH_LONG).show();
+						"unknown exception！Please checking logs in sd card.", Toast.LENGTH_LONG).show();
 				Looper.loop();
+
+				android.os.Process.killProcess(android.os.Process.myPid());
+				System.exit(0);
 			}
 		}).start();
 		// 收集设备参数信息
@@ -160,8 +166,7 @@ public class CrashHandler implements UncaughtExceptionHandler {
 			sb.append("\n");
 		}
 
-		File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath()
-				+File.separator+System.currentTimeMillis()+".txt");
+		File file = new File(UVCCameraHelper.ROOT_PATH + MyApplication.DIRECTORY_NAME +"/log.txt");
 		FileOutputStream fos = null;
 		try {
 			fos = new FileOutputStream(file);
diff --git a/app/src/main/java/com/jiangdg/usbcamera/view/SplashActivity.java b/app/src/main/java/com/jiangdg/usbcamera/view/SplashActivity.java
new file mode 100644
index 0000000..1887139
--- /dev/null
+++ b/app/src/main/java/com/jiangdg/usbcamera/view/SplashActivity.java
@@ -0,0 +1,99 @@
+package com.jiangdg.usbcamera.view;
+
+import android.Manifest;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.Handler;
+import android.support.annotation.NonNull;
+import android.support.v4.app.ActivityCompat;
+import android.support.v4.content.ContextCompat;
+import android.support.v7.app.AppCompatActivity;
+import android.view.WindowManager;
+import android.widget.Toast;
+
+import com.jiangdg.usbcamera.R;
+
+import java.util.ArrayList;
+import java.util.List;
+
+
+/**
+ * permission checking
+ * Created by jiangdongguo on 2019/6/27.
+ */
+
+public class SplashActivity extends AppCompatActivity {
+    private static final String[] REQUIRED_PERMISSION_LIST = new String[]{
+            Manifest.permission.WRITE_EXTERNAL_STORAGE,
+            Manifest.permission.RECORD_AUDIO,
+    };
+    private static final int REQUEST_CODE = 1;
+    private List<String> mMissPermissions = new ArrayList<>();
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
+        setContentView(R.layout.activity_splash);
+
+        if (isVersionM()) {
+            checkAndRequestPermissions();
+        } else {
+            startMainActivity();
+        }
+    }
+
+    private boolean isVersionM() {
+        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP;
+    }
+
+    private void checkAndRequestPermissions() {
+        mMissPermissions.clear();
+        for (String permission : REQUIRED_PERMISSION_LIST) {
+            int result = ContextCompat.checkSelfPermission(this, permission);
+            if (result != PackageManager.PERMISSION_GRANTED) {
+                mMissPermissions.add(permission);
+            }
+        }
+        // check permissions has granted
+        if (mMissPermissions.isEmpty()) {
+            startMainActivity();
+        } else {
+            ActivityCompat.requestPermissions(this,
+                    mMissPermissions.toArray(new String[mMissPermissions.size()]),
+                    REQUEST_CODE);
+        }
+    }
+
+    @Override
+    public void onRequestPermissionsResult(final int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+        if (requestCode == REQUEST_CODE) {
+            for (int i = grantResults.length - 1; i >= 0; i--) {
+                if (grantResults[i] == PackageManager.PERMISSION_GRANTED) {
+                    mMissPermissions.remove(permissions[i]);
+                }
+            }
+        }
+        // Get permissions success or not
+        if (mMissPermissions.isEmpty()) {
+            startMainActivity();
+        } else {
+            Toast.makeText(SplashActivity.this, "get permissions failed,exiting...",Toast.LENGTH_SHORT).show();
+            SplashActivity.this.finish();
+        }
+    }
+
+    private void startMainActivity() {
+        new Handler().postDelayed(new Runnable() {
+            @Override
+            public void run() {
+                startActivity(new Intent(SplashActivity.this, USBCameraActivity.class));
+                SplashActivity.this.finish();
+            }
+        }, 3000);
+    }
+}
+
diff --git a/app/src/main/java/com/jiangdg/usbcamera/view/USBCameraActivity.java b/app/src/main/java/com/jiangdg/usbcamera/view/USBCameraActivity.java
index c6ba68f..d76a0ac 100644
--- a/app/src/main/java/com/jiangdg/usbcamera/view/USBCameraActivity.java
+++ b/app/src/main/java/com/jiangdg/usbcamera/view/USBCameraActivity.java
@@ -26,6 +26,7 @@ import android.widget.Toast;
 
 import com.jiangdg.usbcamera.R;
 import com.jiangdg.usbcamera.UVCCameraHelper;
+import com.jiangdg.usbcamera.application.MyApplication;
 import com.jiangdg.usbcamera.utils.FileUtils;
 import com.serenegiant.usb.CameraDialog;
 import com.serenegiant.usb.Size;
@@ -226,7 +227,7 @@ public class USBCameraActivity extends AppCompatActivity implements CameraDialog
                     showShortMsg("sorry,camera open failed");
                     return super.onOptionsItemSelected(item);
                 }
-                String picPath = UVCCameraHelper.ROOT_PATH + System.currentTimeMillis()
+                String picPath = UVCCameraHelper.ROOT_PATH + MyApplication.DIRECTORY_NAME +"images/"+ System.currentTimeMillis()
                         + UVCCameraHelper.SUFFIX_JPEG;
                 mCameraHelper.capturePicture(picPath, new AbstractUVCCameraHandler.OnCaptureListener() {
                     @Override
@@ -242,7 +243,7 @@ public class USBCameraActivity extends AppCompatActivity implements CameraDialog
                     return super.onOptionsItemSelected(item);
                 }
                 if (!mCameraHelper.isPushing()) {
-                    String videoPath = UVCCameraHelper.ROOT_PATH + System.currentTimeMillis();
+                    String videoPath = UVCCameraHelper.ROOT_PATH + MyApplication.DIRECTORY_NAME +"videos/"+ System.currentTimeMillis();
                     FileUtils.createfile(FileUtils.ROOT_PATH + "test666.h264");
                     // if you want to record,please create RecordParams like this
                     RecordParams params = new RecordParams();
diff --git a/app/src/main/res/layout/activity_splash.xml b/app/src/main/res/layout/activity_splash.xml
new file mode 100644
index 0000000..e0951d2
--- /dev/null
+++ b/app/src/main/res/layout/activity_splash.xml
@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical" android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <TextView
+        android:layout_width="410dp"
+        android:layout_height="0dp"
+        android:layout_weight="1"
+        android:gravity="center_horizontal|center_vertical"
+        android:text="Welcome to use!"
+        android:textSize="28sp"
+        android:textStyle="bold" />
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center_horizontal|center_vertical"
+        android:textSize="14sp"
+        android:textStyle="italic"
+        android:text="Author: jiangdongguo"/>
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center_horizontal|center_vertical"
+        android:layout_marginTop="5dp"
+        android:textStyle="italic"
+        android:textSize="14sp"
+        android:text="Email:765067602@qq.com"/>
+    <TextView
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:text="last modify 2019.6"
+        android:textSize="16sp"
+        android:textStyle="bold"
+        android:gravity="bottom|center_horizontal"
+        android:paddingBottom="20dp"
+        android:layout_weight="1"/>
+</LinearLayout>
\ No newline at end of file
diff --git a/app/src/main/res/mipmap-hdpi/ic_launcher.png b/app/src/main/res/mipmap-hdpi/ic_launcher.png
index cde69bc..c96d22b 100644
Binary files a/app/src/main/res/mipmap-hdpi/ic_launcher.png and b/app/src/main/res/mipmap-hdpi/ic_launcher.png differ
diff --git a/app/src/main/res/mipmap-mdpi/ic_launcher.png b/app/src/main/res/mipmap-mdpi/ic_launcher.png
index c133a0c..c96d22b 100644
Binary files a/app/src/main/res/mipmap-mdpi/ic_launcher.png and b/app/src/main/res/mipmap-mdpi/ic_launcher.png differ
diff --git a/app/src/main/res/mipmap-xhdpi/ic_launcher.png b/app/src/main/res/mipmap-xhdpi/ic_launcher.png
index bfa42f0..c96d22b 100644
Binary files a/app/src/main/res/mipmap-xhdpi/ic_launcher.png and b/app/src/main/res/mipmap-xhdpi/ic_launcher.png differ
diff --git a/app/src/main/res/mipmap-xxhdpi/ic_launcher.png b/app/src/main/res/mipmap-xxhdpi/ic_launcher.png
index 324e72c..c96d22b 100644
Binary files a/app/src/main/res/mipmap-xxhdpi/ic_launcher.png and b/app/src/main/res/mipmap-xxhdpi/ic_launcher.png differ
diff --git a/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png b/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
index aee44e1..c96d22b 100644
Binary files a/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png and b/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png differ
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index c9ecc62..60b5af8 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1,3 +1,3 @@
 <resources>
-    <string name="app_name">UVCCamera</string>
+    <string name="app_name">AndroidUSBCamera</string>
 </resources>
diff --git a/build.gradle b/build.gradle
index d525477..22ea390 100644
--- a/build.gradle
+++ b/build.gradle
@@ -5,7 +5,6 @@ buildscript {
         jcenter()
     }
     dependencies {
-        // gradle插件版本
         classpath 'com.android.tools.build:gradle:3.2.1'
         classpath 'com.github.dcendents:android-maven-gradle-plugin:2.0'
     }
@@ -28,7 +27,7 @@ ext {
     commonLibVersion= '2.12.4'
     versionCompiler = 27
     versionTarget = 27
-    minSdkVersion = 21
+    minSdkVersion = 23
     versionNameString = '1.0.0'
     javaSourceCompatibility = JavaVersion.VERSION_1_8
     javaTargetCompatibility = JavaVersion.VERSION_1_8
diff --git a/libusbcamera/src/main/java/com/jiangdg/usbcamera/utils/FileUtils.java b/libusbcamera/src/main/java/com/jiangdg/usbcamera/utils/FileUtils.java
index cf5af28..ab4f9f4 100644
--- a/libusbcamera/src/main/java/com/jiangdg/usbcamera/utils/FileUtils.java
+++ b/libusbcamera/src/main/java/com/jiangdg/usbcamera/utils/FileUtils.java
@@ -7,7 +7,7 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 
-/** 创建文件
+/**
  *
  * Created by jiangdongguo on 2017/10/18.
  */