diff --git a/app/src/main/java/com/simplemobiletools/gallery/Config.java b/app/src/main/java/com/simplemobiletools/gallery/Config.java
index 89530e046..9d7e98bda 100644
--- a/app/src/main/java/com/simplemobiletools/gallery/Config.java
+++ b/app/src/main/java/com/simplemobiletools/gallery/Config.java
@@ -29,4 +29,12 @@ public class Config {
     public void setIsDarkTheme(boolean isDarkTheme) {
         mPrefs.edit().putBoolean(Constants.IS_DARK_THEME, isDarkTheme).apply();
     }
+
+    public int getSorting() {
+        return mPrefs.getInt(Constants.SORT_ORDER, Constants.SORT_BY_DATE | Constants.SORT_DESCENDING);
+    }
+
+    public void setSorting(int order) {
+        mPrefs.edit().putInt(Constants.SORT_ORDER, order).apply();
+    }
 }
diff --git a/app/src/main/java/com/simplemobiletools/gallery/Constants.java b/app/src/main/java/com/simplemobiletools/gallery/Constants.java
index 9f99435bf..0b572fcc4 100644
--- a/app/src/main/java/com/simplemobiletools/gallery/Constants.java
+++ b/app/src/main/java/com/simplemobiletools/gallery/Constants.java
@@ -11,4 +11,12 @@ public class Constants {
     public static final String PREFS_KEY = "Gallery";
     public static final String IS_FIRST_RUN = "is_first_run";
     public static final String IS_DARK_THEME = "is_dark_theme";
+    public static final String SORT_ORDER = "sort_order";
+
+    // sorting
+    public static final int SORT_BY_NAME = 1;
+    public static final int SORT_BY_DATE = 2;
+    public static final int SORT_BY_SIZE = 4;
+
+    public static final int SORT_DESCENDING = 1024;
 }
diff --git a/app/src/main/java/com/simplemobiletools/gallery/activities/MainActivity.java b/app/src/main/java/com/simplemobiletools/gallery/activities/MainActivity.java
index 8d4bd8031..b7f6f0954 100644
--- a/app/src/main/java/com/simplemobiletools/gallery/activities/MainActivity.java
+++ b/app/src/main/java/com/simplemobiletools/gallery/activities/MainActivity.java
@@ -334,8 +334,8 @@ public class MainActivity extends SimpleActivity
         final TextView dirPath = (TextView) renameDirView.findViewById(R.id.directory_path);
         dirPath.setText(dir.getParent() + "/");
 
-        builder.setPositiveButton("OK", null);
-        builder.setNegativeButton("Cancel", null);
+        builder.setPositiveButton(android.R.string.ok, null);
+        builder.setNegativeButton(android.R.string.cancel, null);
 
         final AlertDialog alertDialog = builder.create();
         alertDialog.show();
diff --git a/app/src/main/java/com/simplemobiletools/gallery/activities/MediaActivity.java b/app/src/main/java/com/simplemobiletools/gallery/activities/MediaActivity.java
index 19215de76..314453cec 100644
--- a/app/src/main/java/com/simplemobiletools/gallery/activities/MediaActivity.java
+++ b/app/src/main/java/com/simplemobiletools/gallery/activities/MediaActivity.java
@@ -1,6 +1,7 @@
 package com.simplemobiletools.gallery.activities;
 
 import android.app.WallpaperManager;
+import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.res.Resources;
 import android.database.Cursor;
@@ -14,6 +15,7 @@ import android.provider.MediaStore;
 import android.support.design.widget.CoordinatorLayout;
 import android.support.design.widget.Snackbar;
 import android.support.v4.widget.SwipeRefreshLayout;
+import android.support.v7.app.AlertDialog;
 import android.util.Log;
 import android.util.SparseBooleanArray;
 import android.view.ActionMode;
@@ -24,6 +26,8 @@ import android.view.MotionEvent;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.GridView;
+import android.widget.RadioButton;
+import android.widget.RadioGroup;
 
 import com.bumptech.glide.Glide;
 import com.bumptech.glide.request.animation.GlideAnimation;
@@ -134,12 +138,63 @@ public class MediaActivity extends SimpleActivity
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
             case R.id.sort:
+                showSortingDialog();
                 return true;
             default:
                 return super.onOptionsItemSelected(item);
         }
     }
 
+    private void showSortingDialog() {
+        final View sortingView = getLayoutInflater().inflate(R.layout.change_sorting, null);
+
+        final AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        builder.setTitle(getResources().getString(R.string.sort_by));
+        builder.setView(sortingView);
+
+        final int currSorting = mConfig.getSorting();
+        final RadioGroup sortingRadio = (RadioGroup) sortingView.findViewById(R.id.dialog_radio_sorting);
+        RadioButton sortBtn = (RadioButton) sortingRadio.findViewById(R.id.dialog_radio_name);
+        if ((currSorting & Constants.SORT_BY_DATE) != 0) {
+            sortBtn = (RadioButton) sortingRadio.findViewById(R.id.dialog_radio_date);
+        } else if ((currSorting & Constants.SORT_BY_SIZE) != 0) {
+            sortBtn = (RadioButton) sortingRadio.findViewById(R.id.dialog_radio_size);
+        }
+        sortBtn.setChecked(true);
+
+        final RadioGroup orderRadio = (RadioGroup) sortingView.findViewById(R.id.dialog_radio_order);
+        RadioButton orderBtn = (RadioButton) orderRadio.findViewById(R.id.dialog_radio_ascending);
+        if ((currSorting & Constants.SORT_DESCENDING) != 0) {
+            orderBtn = (RadioButton) orderRadio.findViewById(R.id.dialog_radio_descending);
+        }
+        orderBtn.setChecked(true);
+
+        builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
+            @Override
+            public void onClick(DialogInterface dialog, int which) {
+                int sorting = Constants.SORT_BY_NAME;
+                switch (sortingRadio.getCheckedRadioButtonId()) {
+                    case R.id.dialog_radio_date:
+                        sorting = Constants.SORT_BY_DATE;
+                        break;
+                    case R.id.dialog_radio_size:
+                        sorting = Constants.SORT_BY_SIZE;
+                        break;
+                    default:
+                        break;
+                }
+
+                if (orderRadio.getCheckedRadioButtonId() == R.id.dialog_radio_descending) {
+                    sorting |= Constants.SORT_DESCENDING;
+                }
+                mConfig.setSorting(sorting);
+                initializeGallery();
+            }
+        });
+        builder.setNegativeButton(android.R.string.cancel, null);
+        builder.show();
+    }
+
     private void deleteDirectoryIfEmpty() {
         final File file = new File(mPath);
         if (file.isDirectory() && file.listFiles().length == 0) {
@@ -176,7 +231,7 @@ public class MediaActivity extends SimpleActivity
                         if (file.exists()) {
                             final int dateIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATE_TAKEN);
                             final long timestamp = cursor.getLong(dateIndex);
-                            media.add(new Medium(curPath, (i == 1), timestamp));
+                            media.add(new Medium(curPath, (i == 1), timestamp, file.length()));
                         } else {
                             invalidFiles.add(file.getAbsolutePath());
                         }
@@ -186,6 +241,7 @@ public class MediaActivity extends SimpleActivity
             }
         }
 
+        Medium.mOrder = mConfig.getSorting();
         Collections.sort(media);
 
         final String[] invalids = invalidFiles.toArray(new String[invalidFiles.size()]);
diff --git a/app/src/main/java/com/simplemobiletools/gallery/activities/PhotoVideoActivity.java b/app/src/main/java/com/simplemobiletools/gallery/activities/PhotoVideoActivity.java
index 17a5e635e..eb6860196 100644
--- a/app/src/main/java/com/simplemobiletools/gallery/activities/PhotoVideoActivity.java
+++ b/app/src/main/java/com/simplemobiletools/gallery/activities/PhotoVideoActivity.java
@@ -15,6 +15,8 @@ import com.simplemobiletools.gallery.fragments.VideoFragment;
 import com.simplemobiletools.gallery.fragments.ViewPagerFragment;
 import com.simplemobiletools.gallery.models.Medium;
 
+import java.io.File;
+
 public class PhotoVideoActivity extends SimpleActivity implements ViewPagerFragment.FragmentClickListener {
     private static ActionBar mActionbar;
     private static Uri mUri;
@@ -37,7 +39,8 @@ public class PhotoVideoActivity extends SimpleActivity implements ViewPagerFragm
         hideSystemUI();
 
         final Bundle bundle = new Bundle();
-        final Medium medium = new Medium(mUri.toString(), mIsVideo, 0);
+        final File file = new File(mUri.toString());
+        final Medium medium = new Medium(mUri.toString(), mIsVideo, 0, file.length());
         bundle.putSerializable(Constants.MEDIUM, medium);
 
         if (savedInstanceState == null) {
diff --git a/app/src/main/java/com/simplemobiletools/gallery/activities/ViewPagerActivity.java b/app/src/main/java/com/simplemobiletools/gallery/activities/ViewPagerActivity.java
index 094115d16..b103ea266 100644
--- a/app/src/main/java/com/simplemobiletools/gallery/activities/ViewPagerActivity.java
+++ b/app/src/main/java/com/simplemobiletools/gallery/activities/ViewPagerActivity.java
@@ -70,9 +70,11 @@ public class ViewPagerActivity extends SimpleActivity
             try {
                 final String[] proj = {MediaStore.Images.Media.DATA};
                 cursor = getContentResolver().query(uri, proj, null, null, null);
-                final int dataIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
-                cursor.moveToFirst();
-                mPath = cursor.getString(dataIndex);
+                if (cursor != null) {
+                    final int dataIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
+                    cursor.moveToFirst();
+                    mPath = cursor.getString(dataIndex);
+                }
             } finally {
                 if (cursor != null) {
                     cursor.close();
@@ -226,8 +228,8 @@ public class ViewPagerActivity extends SimpleActivity
         builder.setTitle(getResources().getString(R.string.rename_file));
         builder.setView(renameFileView);
 
-        builder.setPositiveButton("OK", null);
-        builder.setNegativeButton("Cancel", null);
+        builder.setPositiveButton(android.R.string.ok, null);
+        builder.setNegativeButton(android.R.string.cancel, null);
 
         final AlertDialog alertDialog = builder.create();
         alertDialog.show();
@@ -246,7 +248,7 @@ public class ViewPagerActivity extends SimpleActivity
 
                 if (file.renameTo(newFile)) {
                     final int currItem = mPager.getCurrentItem();
-                    mMedia.set(currItem, new Medium(newFile.getAbsolutePath(), mMedia.get(currItem).getIsVideo(), 0));
+                    mMedia.set(currItem, new Medium(newFile.getAbsolutePath(), mMedia.get(currItem).getIsVideo(), 0, file.length()));
 
                     final String[] changedFiles = {file.getAbsolutePath(), newFile.getAbsolutePath()};
                     MediaScannerConnection.scanFile(getApplicationContext(), changedFiles, null, null);
@@ -294,7 +296,7 @@ public class ViewPagerActivity extends SimpleActivity
             }
             final String where = MediaStore.Images.Media.DATA + " like ? ";
             final String[] args = new String[]{mDirectory + "%"};
-            final String[] columns = {MediaStore.Images.Media.DATA, MediaStore.Images.Media.DATE_TAKEN};
+            final String[] columns = {MediaStore.Images.Media.DATA, MediaStore.Images.Media.DATE_TAKEN, MediaStore.Images.Media.SIZE};
             final Cursor cursor = getContentResolver().query(uri, columns, where, args, null);
             final String pattern = Pattern.quote(mDirectory) + "/[^/]*";
 
@@ -305,13 +307,17 @@ public class ViewPagerActivity extends SimpleActivity
                     if (curPath.matches(pattern) && !curPath.equals(mToBeDeleted) && !curPath.equals(mBeingDeleted)) {
                         final int dateIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATE_TAKEN);
                         final long timestamp = cursor.getLong(dateIndex);
-                        media.add(new Medium(curPath, i == 1, timestamp));
+
+                        final int sizeIndex = cursor.getColumnIndex(MediaStore.Images.Media.SIZE);
+                        final long size = cursor.getLong(sizeIndex);
+                        media.add(new Medium(curPath, i == 1, timestamp, size));
                     }
                 } while (cursor.moveToNext());
                 cursor.close();
             }
         }
 
+        Medium.mOrder = mConfig.getSorting();
         Collections.sort(media);
         int j = 0;
         for (Medium medium : media) {
diff --git a/app/src/main/java/com/simplemobiletools/gallery/models/Medium.java b/app/src/main/java/com/simplemobiletools/gallery/models/Medium.java
index c443536ff..adc128057 100644
--- a/app/src/main/java/com/simplemobiletools/gallery/models/Medium.java
+++ b/app/src/main/java/com/simplemobiletools/gallery/models/Medium.java
@@ -1,5 +1,7 @@
 package com.simplemobiletools.gallery.models;
 
+import com.simplemobiletools.gallery.Constants;
+
 import java.io.Serializable;
 
 public class Medium implements Serializable, Comparable {
@@ -7,11 +9,14 @@ public class Medium implements Serializable, Comparable {
     private final String mPath;
     private final boolean mIsVideo;
     private final long mTimestamp;
+    private final long mSize;
+    public static int mOrder;
 
-    public Medium(String path, boolean isVideo, long timestamp) {
+    public Medium(String path, boolean isVideo, long timestamp, long size) {
         mPath = path;
         mIsVideo = isVideo;
         mTimestamp = timestamp;
+        mSize = size;
     }
 
     public String getPath() {
@@ -26,6 +31,10 @@ public class Medium implements Serializable, Comparable {
         return mTimestamp;
     }
 
+    public long getSize() {
+        return mSize;
+    }
+
     public boolean isGif() {
         return getPath().endsWith(".gif");
     }
@@ -33,12 +42,19 @@ public class Medium implements Serializable, Comparable {
     @Override
     public int compareTo(Object object) {
         final Medium medium = (Medium) object;
-        if (mTimestamp < medium.getTimestamp()) {
-            return 1;
-        } else if (mTimestamp > medium.getTimestamp()) {
-            return -1;
+        int res;
+        if ((mOrder & Constants.SORT_BY_NAME) == Constants.SORT_BY_NAME) {
+            res = mPath.compareTo(medium.getPath());
+        } else if ((mOrder & Constants.SORT_BY_DATE) == Constants.SORT_BY_DATE) {
+            res = (mTimestamp > medium.getTimestamp()) ? 1 : -1;
+        } else {
+            res = (mSize > medium.getSize()) ? 1 : -1;
         }
-        return 0;
+
+        if ((mOrder & Constants.SORT_DESCENDING) == Constants.SORT_DESCENDING) {
+            res *= -1;
+        }
+        return res;
     }
 
     @Override
diff --git a/app/src/main/res/layout/change_sorting.xml b/app/src/main/res/layout/change_sorting.xml
new file mode 100644
index 000000000..65a131705
--- /dev/null
+++ b/app/src/main/res/layout/change_sorting.xml
@@ -0,0 +1,69 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout android:id="@+id/dialog_holder"
+              xmlns:android="http://schemas.android.com/apk/res/android"
+              android:layout_width="match_parent"
+              android:layout_height="match_parent"
+              android:orientation="vertical"
+              android:paddingLeft="@dimen/activity_margin"
+              android:paddingRight="@dimen/activity_margin"
+              android:paddingTop="@dimen/activity_margin">
+
+    <RadioGroup
+        android:id="@+id/dialog_radio_sorting"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <RadioButton
+            android:id="@+id/dialog_radio_name"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingBottom="@dimen/medium_padding"
+            android:paddingTop="@dimen/medium_padding"
+            android:text="@string/name"/>
+
+        <RadioButton
+            android:id="@+id/dialog_radio_date"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingBottom="@dimen/medium_padding"
+            android:paddingTop="@dimen/medium_padding"
+            android:text="@string/date"/>
+
+        <RadioButton
+            android:id="@+id/dialog_radio_size"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingBottom="@dimen/medium_padding"
+            android:paddingTop="@dimen/medium_padding"
+            android:text="@string/size"/>
+    </RadioGroup>
+
+    <ImageView
+        android:layout_width="match_parent"
+        android:layout_height="1px"
+        android:layout_marginBottom="@dimen/medium_padding"
+        android:layout_marginTop="@dimen/medium_padding"
+        android:background="@color/light_grey"/>
+
+    <RadioGroup
+        android:id="@+id/dialog_radio_order"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <RadioButton
+            android:id="@+id/dialog_radio_ascending"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingBottom="@dimen/medium_padding"
+            android:paddingTop="@dimen/medium_padding"
+            android:text="@string/ascending"/>
+
+        <RadioButton
+            android:id="@+id/dialog_radio_descending"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingBottom="@dimen/medium_padding"
+            android:paddingTop="@dimen/medium_padding"
+            android:text="@string/descending"/>
+    </RadioGroup>
+</LinearLayout>
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index a00e2ebf5..3fbae7ad2 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -7,4 +7,5 @@
     <color name="activated_item_foreground">#99ff6f00</color>
     <color name="tmb_background">#ff222222</color>
     <color name="actionbar_grey">#55000000</color>
+    <color name="light_grey">#aa888888</color>
 </resources>
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
index 10e019eea..ce273a062 100644
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -8,20 +8,20 @@
         <item name="android:textSize">@dimen/normal_text_size</item>
     </style>
 
+    <style name="AppTheme.Dark" parent="Theme.AppCompat">
+        <item name="colorPrimary">@color/colorPrimary</item>
+        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
+        <item name="colorAccent">@color/colorAccent</item>
+        <item name="actionBarStyle">@style/AppTheme.ActionBarStyle</item>
+        <item name="android:textSize">@dimen/normal_text_size</item>
+    </style>
+
     <style name="FullScreenTheme.Base" parent="AppTheme">
         <item name="android:windowContentOverlay">@null</item>
         <item name="actionBarStyle">@style/MyFullScreenActionBar</item>
         <item name="android:actionBarStyle">@style/MyFullScreenActionBar</item>
     </style>
 
-    <style name="AppTheme.Dark" parent="Theme.AppCompat">
-        <item name="colorPrimary">@color/colorPrimary</item>
-        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
-        <item name="colorAccent">@color/colorAccent</item>
-        <item name="actionBarStyle">@style/AppTheme.ActionBarStyle</item>
-        <item name="android:textSize">@dimen/normal_text_size</item>
-    </style>
-
     <style name="FullScreenTheme.Base.Dark" parent="AppTheme.Dark">
         <item name="android:windowContentOverlay">@null</item>
         <item name="actionBarStyle">@style/MyFullScreenActionBar</item>