diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 6d94ab59..010bcad5 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -7,6 +7,7 @@
 
     <uses-feature android:glEsVersion="0x00020000" android:required="true" />
     <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 
     <application
         android:allowBackup="true"
diff --git a/app/src/main/java/space/celestia/mobilecelestia/CelestiaFragment.kt b/app/src/main/java/space/celestia/mobilecelestia/CelestiaFragment.kt
index 8a3938aa..94231f94 100644
--- a/app/src/main/java/space/celestia/mobilecelestia/CelestiaFragment.kt
+++ b/app/src/main/java/space/celestia/mobilecelestia/CelestiaFragment.kt
@@ -29,6 +29,7 @@ class CelestiaFragment : Fragment(), GLSurfaceView.Renderer {
     // MARK: Celestia
     private var pathToLoad: String? = null
     private var cfgToLoad: String? = null
+    private var addonToLoad: String? = null
     private val core by lazy { CelestiaAppCore.shared() }
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -37,6 +38,7 @@ class CelestiaFragment : Fragment(), GLSurfaceView.Renderer {
         arguments?.let {
             pathToLoad = it.getString(ARG_DATA_DIR)
             cfgToLoad = it.getString(ARG_CFG_FILE)
+            addonToLoad = it.getString(ARG_ADDON_DIR)
         }
 
         retainInstance = true
@@ -87,12 +89,14 @@ class CelestiaFragment : Fragment(), GLSurfaceView.Renderer {
         glViewContainer?.addView(glView, FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT)
     }
 
-    private fun loadCelestia(path: String, cfg: String) {
+    private fun loadCelestia(path: String, cfg: String, addon: String?) {
         CelestiaAppCore.chdir(path)
 
         CelestiaAppCore.setLocaleDirectoryPath("$path/locale", Locale.getDefault().toString())
 
-        if (!core.startSimulation(cfg, null, AppStatusReporter.shared())) {
+        val extraDirs = if (addon != null) arrayOf(addon) else null
+
+        if (!core.startSimulation(cfg, extraDirs, AppStatusReporter.shared())) {
             AppStatusReporter.shared().celestiaLoadResult(false)
             return
         }
@@ -124,7 +128,7 @@ class CelestiaFragment : Fragment(), GLSurfaceView.Renderer {
         glView?.queueEvent {
             // Celestia initialization have to be called with an OpenGL context
             if (pathToLoad != null && cfgToLoad != null) {
-                loadCelestia(pathToLoad!!, cfgToLoad!!)
+                loadCelestia(pathToLoad!!, cfgToLoad!!, addonToLoad)
             }
         }
     }
@@ -145,14 +149,18 @@ class CelestiaFragment : Fragment(), GLSurfaceView.Renderer {
     companion object {
         private const val ARG_DATA_DIR = "data"
         private const val ARG_CFG_FILE = "cfg"
+        private const val ARG_ADDON_DIR = "addon"
 
         private const val TAG = "CelestiaFragment"
 
-        fun newInstance(data: String, cfg: String) =
+        fun newInstance(data: String, cfg: String, addon: String?) =
             CelestiaFragment().apply {
                 arguments = Bundle().apply {
                     putString(ARG_DATA_DIR, data)
                     putString(ARG_CFG_FILE, cfg)
+                    if (addon != null) {
+                        putString(ARG_ADDON_DIR, addon)
+                    }
                 }
             }
     }
diff --git a/app/src/main/java/space/celestia/mobilecelestia/MainActivity.kt b/app/src/main/java/space/celestia/mobilecelestia/MainActivity.kt
index 94977c74..56d01282 100644
--- a/app/src/main/java/space/celestia/mobilecelestia/MainActivity.kt
+++ b/app/src/main/java/space/celestia/mobilecelestia/MainActivity.kt
@@ -3,7 +3,9 @@ package space.celestia.mobilecelestia
 import android.app.DatePickerDialog
 import android.app.TimePickerDialog
 import android.content.Intent
+import android.content.pm.PackageManager
 import android.net.Uri
+import android.os.Build
 import android.os.Bundle
 import android.util.Log
 import android.view.View
@@ -12,6 +14,7 @@ import android.view.WindowManager
 import android.widget.DatePicker
 import android.widget.ImageButton
 import androidx.appcompat.app.AppCompatActivity
+import androidx.core.app.ActivityCompat
 import androidx.core.app.ShareCompat
 import androidx.fragment.app.Fragment
 import com.google.gson.Gson
@@ -68,12 +71,10 @@ class MainActivity : AppCompatActivity(),
     AboutFragment.Listener,
     AppStatusReporter.Listener {
 
-    private val celestiaFolderName = "CelestiaResources"
-    private val celestiaCfgName = "celestia.cfg"
-
     private val preferenceManager by lazy { PreferenceManager(this, "celestia") }
     private val settingManager by lazy { PreferenceManager(this, "celestia_setting") }
     private val celestiaParentPath by lazy { this.filesDir.absolutePath }
+    private var addonPath: String? = null
 
     private val core by lazy { CelestiaAppCore.shared() }
     private var currentSelection: CelestiaSelection? = null
@@ -230,7 +231,7 @@ class MainActivity : AppCompatActivity(),
 
         GlobalScope.launch(Dispatchers.IO) {
             try {
-                AssetUtils.copyFileOrDir(this@MainActivity, celestiaFolderName, celestiaParentPath)
+                AssetUtils.copyFileOrDir(this@MainActivity, CELESTIA_DATA_FOLDER_NAME, celestiaParentPath)
                 preferenceManager[PreferenceManager.PredefinedKey.DataVersion] = CURRENT_DATA_VERSION
                 withContext(Dispatchers.Main) {
                     copyAssetSuccess()
@@ -357,6 +358,43 @@ class MainActivity : AppCompatActivity(),
     }
 
     private fun copyAssetSuccess() {
+        // Check permission to create folder
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M || ActivityCompat.checkSelfPermission(this, android.Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
+            requestPermissionCompleted()
+            return
+        }
+        // Requesting permission to create add-on folder
+        val permission = arrayOf(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
+        ActivityCompat.requestPermissions(this, permission, WRITE_EXTERNAL_STROAGE_REQUEST)
+    }
+
+    override fun onRequestPermissionsResult(
+        requestCode: Int,
+        permissions: Array<out String>,
+        grantResults: IntArray
+    ) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
+        if (requestCode != WRITE_EXTERNAL_STROAGE_REQUEST) { return }
+        // No matter what the result for permission request, proceed
+        requestPermissionCompleted()
+    }
+
+    private fun requestPermissionCompleted() {
+        // Check permission to create folder
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
+            createAddonFolderCompleted()
+            return
+        }
+
+        // Permission granted, create add-on directory if not exits
+        val folder = getExternalFilesDir(CELESTIA_EXTRA_FOLDER_NAME)
+        if (folder != null && (folder.exists() || folder.mkdir())) {
+            addonPath = folder.absolutePath
+        }
+        createAddonFolderCompleted()
+    }
+
+    private fun createAddonFolderCompleted() {
         // Load library
         AppStatusReporter.shared().updateStatus("Loading library...")
         GlobalScope.launch(Dispatchers.IO) {
@@ -369,7 +407,7 @@ class MainActivity : AppCompatActivity(),
 
     private fun loadLibrarySuccess() {
         // Add gl fragment
-        val celestiaFragment = CelestiaFragment.newInstance("$celestiaParentPath/$celestiaFolderName", "$celestiaParentPath/$celestiaFolderName/$celestiaCfgName")
+        val celestiaFragment = CelestiaFragment.newInstance("$celestiaParentPath/$CELESTIA_DATA_FOLDER_NAME", "$celestiaParentPath/$CELESTIA_DATA_FOLDER_NAME/$CELESTIA_CFG_NAME", addonPath)
         supportFragmentManager
             .beginTransaction()
             .add(R.id.celestia_fragment_container, celestiaFragment)
@@ -772,6 +810,13 @@ class MainActivity : AppCompatActivity(),
 
     companion object {
         private const val CURRENT_DATA_VERSION = "1"
+        private const val WRITE_EXTERNAL_STROAGE_REQUEST = 1
+
+        private const val CELESTIA_DATA_FOLDER_NAME = "CelestiaResources"
+        private const val CELESTIA_CFG_NAME = "celestia.cfg"
+        private const val CELESTIA_EXTRA_FOLDER_NAME = "CelestiaResources/extras"
+
+
         private const val TAG = "MainActivity"
     }
 }