diff --git a/android/app/src/main/kotlin/xyz/project/violet/MainActivity.kt b/android/app/src/main/kotlin/xyz/project/violet/MainActivity.kt
index d2ecae8e4..a9348adba 100644
--- a/android/app/src/main/kotlin/xyz/project/violet/MainActivity.kt
+++ b/android/app/src/main/kotlin/xyz/project/violet/MainActivity.kt
@@ -9,6 +9,7 @@ import android.view.WindowManager
 import io.flutter.embedding.android.FlutterFragmentActivity
 import io.flutter.embedding.engine.FlutterEngine
 import io.flutter.plugin.common.EventChannel
+import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler
 import io.flutter.plugins.GeneratedPluginRegistrant
@@ -17,6 +18,7 @@ class MainActivity : FlutterFragmentActivity() {
     private val VOLUME_CHANNEL = "xyz.project.violet/volume"
     private val NATIVELIBDIR_CHANNEL = "xyz.project.violet/nativelibdir"
     private val EXTERNAL_STORAGE_DIRECTORY_CHANNEL = "xyz.project.violet/externalStorageDirectory"
+    private val MISC_CHANNEL = "xyz.project.violet/misc"
 
     private val EXTERNAL_STORAGE_DIRECTORY_METHODS = mapOf(
             "getExternalStorageDirectory" to MethodCallHandler { call, result ->
@@ -76,6 +78,13 @@ class MainActivity : FlutterFragmentActivity() {
                 result.notImplemented()
             }
         }
+
+        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, MISC_CHANNEL).setMethodCallHandler { call, result ->
+            when (call.method) {
+                "finishMainActivity" -> finishMainActivity(call, result)
+                else -> result.notImplemented()
+            }
+        }
     }
 
     override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {
@@ -86,4 +95,9 @@ class MainActivity : FlutterFragmentActivity() {
 
         return super.onKeyDown(keyCode, event)
     }
+
+    private fun finishMainActivity(call: MethodCall, result: MethodChannel.Result) {
+        finish()
+        result.success(null)
+    }
 }
diff --git a/assets/locale/en.json b/assets/locale/en.json
index c706b7054..6480d776f 100644
--- a/assets/locale/en.json
+++ b/assets/locale/en.json
@@ -305,5 +305,6 @@
   "lab": "Laboratory",
   "realtimeuserrecord": "Real Time User Record",
   "manualupdate": "Manual Update",
-  "cannotuseios": "You cannot use update on iOS :("
+  "cannotuseios": "You cannot use update on iOS :(",
+  "exitTheApp": "Exit the app"
 }
diff --git a/assets/locale/eo.json b/assets/locale/eo.json
index d8b64da18..c6e315c79 100644
--- a/assets/locale/eo.json
+++ b/assets/locale/eo.json
@@ -305,5 +305,6 @@
   "lab": "Laboratory",
   "realtimeuserrecord": "Real Time User Record",
   "manualupdate": "Manual Update",
-  "cannotuseios": "You cannot use update on iOS :("
+  "cannotuseios": "You cannot use update on iOS :(",
+  "exitTheApp": "Exit the app"
 }
diff --git a/assets/locale/it.json b/assets/locale/it.json
index cdcaf6afb..eb271b286 100644
--- a/assets/locale/it.json
+++ b/assets/locale/it.json
@@ -305,5 +305,6 @@
   "lab": "Laboratory",
   "realtimeuserrecord": "Real Time User Record",
   "manualupdate": "Manual Update",
-  "cannotuseios": "You cannot use update on iOS :("
+  "cannotuseios": "You cannot use update on iOS :(",
+  "exitTheApp": "Exit the app"
 }
diff --git a/assets/locale/ja.json b/assets/locale/ja.json
index f3009274c..cbd2907a4 100644
--- a/assets/locale/ja.json
+++ b/assets/locale/ja.json
@@ -305,5 +305,6 @@
   "lab": "Laboratory",
   "realtimeuserrecord": "Real Time User Record",
   "manualupdate": "Manual Update",
-  "cannotuseios": "You cannot use update on iOS :("
+  "cannotuseios": "You cannot use update on iOS :(",
+  "exitTheApp": "Exit the app"
 }
diff --git a/assets/locale/ko.json b/assets/locale/ko.json
index 2158012d3..dfda64f38 100644
--- a/assets/locale/ko.json
+++ b/assets/locale/ko.json
@@ -305,5 +305,6 @@
   "lab": "실험실",
   "realtimeuserrecord": "실시간 유저 레코드",
   "manualupdate": "수동 업데이트",
-  "cannotuseios": "iOS에선 사용할 수 없어요 :("
+  "cannotuseios": "iOS에선 사용할 수 없어요 :(",
+  "exitTheApp": "앱 종료하기"
 }
diff --git a/assets/locale/pt.json b/assets/locale/pt.json
index 2a42c0073..61d8e90f6 100644
--- a/assets/locale/pt.json
+++ b/assets/locale/pt.json
@@ -305,5 +305,6 @@
   "lab": "Laboratory",
   "realtimeuserrecord": "Real Time User Record",
   "manualupdate": "Manual Update",
-  "cannotuseios": "You cannot use update on iOS :("
+  "cannotuseios": "You cannot use update on iOS :(",
+  "exitTheApp": "Exit the app"
 }
diff --git a/assets/locale/zh.json b/assets/locale/zh.json
index fa6c0983f..3a6683edc 100644
--- a/assets/locale/zh.json
+++ b/assets/locale/zh.json
@@ -305,5 +305,6 @@
   "lab": "Laboratory",
   "realtimeuserrecord": "Real Time User Record",
   "manualupdate": "Manual Update",
-  "cannotuseios": "You cannot use update on iOS :("
+  "cannotuseios": "You cannot use update on iOS :(",
+  "exitTheApp": "Exit the app"
 }
diff --git a/assets/locale/zh_Hans.json b/assets/locale/zh_Hans.json
index d8822bfd5..85029def9 100644
--- a/assets/locale/zh_Hans.json
+++ b/assets/locale/zh_Hans.json
@@ -305,5 +305,6 @@
   "lab": "Laboratory",
   "realtimeuserrecord": "Real Time User Record",
   "manualupdate": "Manual Update",
-  "cannotuseios": "You cannot use update on iOS :("
+  "cannotuseios": "You cannot use update on iOS :(",
+  "exitTheApp": "Exit the app"
 }
diff --git a/assets/locale/zh_Hant.json b/assets/locale/zh_Hant.json
index 6a9123087..8d0c87000 100644
--- a/assets/locale/zh_Hant.json
+++ b/assets/locale/zh_Hant.json
@@ -305,5 +305,6 @@
   "lab": "Laboratory",
   "realtimeuserrecord": "Real Time User Record",
   "manualupdate": "Manual Update",
-  "cannotuseios": "You cannot use update on iOS :("
+  "cannotuseios": "You cannot use update on iOS :(",
+  "exitTheApp": "Exit the app"
 }
diff --git a/lib/component/hitomi/population.dart b/lib/component/hitomi/population.dart
index 3f0e386bc..1a9ae7348 100644
--- a/lib/component/hitomi/population.dart
+++ b/lib/component/hitomi/population.dart
@@ -3,6 +3,7 @@
 
 import 'dart:convert';
 import 'dart:io';
+import 'dart:isolate';
 
 import 'package:flutter/services.dart';
 import 'package:violet/database/query.dart';
@@ -15,18 +16,35 @@ class Population {
     String data;
 
     if (Platform.environment.containsKey('FLUTTER_TEST')) {
-      var file = File('/home/ubuntu/violet/assets/rank/population.json');
+      final file = File('/home/ubuntu/violet/assets/rank/population.json');
       data = await file.readAsString();
     } else {
       data = await rootBundle.loadString('assets/rank/population.json');
     }
 
-    List<dynamic> dataPopulation = json.decode(data);
-    population = <int, int>{};
+    Future<Map<int, int>> decodeJsonData() async {
+      final population = <int, int>{};
 
-    for (int i = 0; i < dataPopulation.length; i++) {
-      population[dataPopulation[i] as int] = i;
+      json.decode(
+        data,
+        reviver: (keyObject, valueObject) {
+          if (keyObject == null) {
+            return null;
+          }
+
+          int key = keyObject as int;
+          int value = (valueObject as num).toInt();
+
+          population[value] = key;
+
+          return null;
+        },
+      );
+
+      return population;
     }
+
+    population = await Isolate.run(decodeJsonData);
   }
 
   static void sortByPopulation(List<QueryResult> qr) {
diff --git a/lib/component/hitomi/related.dart b/lib/component/hitomi/related.dart
index c4f51e590..1dd8d9041 100644
--- a/lib/component/hitomi/related.dart
+++ b/lib/component/hitomi/related.dart
@@ -3,6 +3,7 @@
 
 import 'dart:convert';
 import 'dart:io';
+import 'dart:isolate';
 
 import 'package:flutter/services.dart';
 
@@ -13,20 +14,35 @@ class Related {
     String data;
 
     if (Platform.environment.containsKey('FLUTTER_TEST')) {
-      var file = File('/home/ubuntu/violet/assets/rank/related.json');
+      final file = File('/home/ubuntu/violet/assets/rank/related.json');
       data = await file.readAsString();
     } else {
       data = await rootBundle.loadString('assets/rank/related.json');
     }
 
-    Map<String, dynamic> dataMap = json.decode(data);
-
-    related = <int, List<int>>{};
+    Future<Map<int, List<int>>> decodeJsonData() async {
+      final related = <int, List<int>>{};
+
+      json.decode(
+        data,
+        reviver: (key, value) {
+          if (key == null) {
+            return value;
+          }
+
+          if (key is String) {
+            related[int.parse(key)] = (value as List<dynamic>).cast();
+            return null;
+          } else {
+            return value;
+          }
+        },
+      );
+
+      return related;
+    }
 
-    dataMap.entries.forEach((element) {
-      related[int.parse(element.key)] =
-          (element.value as List<dynamic>).map((e) => e as int).toList();
-    });
+    related = await Isolate.run(decodeJsonData);
   }
 
   static bool existsRelated(int articleId) {
diff --git a/lib/component/hitomi/tag_translate.dart b/lib/component/hitomi/tag_translate.dart
index 2c50b4077..ddc9657b2 100644
--- a/lib/component/hitomi/tag_translate.dart
+++ b/lib/component/hitomi/tag_translate.dart
@@ -3,6 +3,7 @@
 
 import 'dart:convert';
 import 'dart:io';
+import 'dart:isolate';
 
 import 'package:flutter/services.dart';
 import 'package:tuple/tuple.dart';
@@ -21,25 +22,51 @@ class TagTranslate {
     String data;
 
     if (Platform.environment.containsKey('FLUTTER_TEST')) {
-      var file = File('/home/ubuntu/violet/assets/locale/tag/korean.json');
+      final file = File('/home/ubuntu/violet/assets/locale/tag/korean.json');
       data = await file.readAsString();
     } else {
       data = await rootBundle
           .loadString('assets/locale/tag/$defaultLanguage.json');
     }
-    Map<String, dynamic> result = json.decode(data);
-
-    _translateMap = <String, String>{};
-    _reverseAndroMap = <String, String>{};
-
-    result.entries.forEach((element) {
-      if (element.value.toString().trim() == '') return;
-      if (_translateMap.containsKey(element.key)) return;
-      _translateMap[element.key] = element.value as String;
-      _reverseAndroMap[disassembly((element.value as String)
-          .replaceAll('female:', '')
-          .replaceAll('male:', ''))] = element.key;
-    });
+
+    Future<(Map<String, String>, Map<String, String>)> decodeJsonData() async {
+      final translateMap = <String, String>{};
+      final reverseAndroMap = <String, String>{};
+
+      json.decode(
+        data,
+        reviver: (keyObject, valueObject) {
+          if (keyObject == null) {
+            return null;
+          }
+
+          final key = keyObject.toString();
+          final value = valueObject.toString();
+
+          if (value.trim().isEmpty) {
+            return null;
+          }
+
+          if (!translateMap.containsKey(key)) {
+            return null;
+          }
+
+          translateMap[key] = value;
+          reverseAndroMap[disassembly(value)
+              .replaceAll('female:', '')
+              .replaceAll('male:', '')] = key;
+
+          return null;
+        },
+      );
+
+      return (translateMap, reverseAndroMap);
+    }
+
+    final (translateMap, reverseAndroMap) = await Isolate.run(decodeJsonData);
+
+    _translateMap = translateMap;
+    _reverseAndroMap = reverseAndroMap;
   }
 
   static String of(String classification, String key) {
diff --git a/lib/pages/database_download/database_download_page.dart b/lib/pages/database_download/database_download_page.dart
index abc618279..f9116dd87 100644
--- a/lib/pages/database_download/database_download_page.dart
+++ b/lib/pages/database_download/database_download_page.dart
@@ -4,10 +4,12 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
+import 'dart:ui';
 
 import 'package:dio/dio.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
+import 'package:flutter/services.dart';
 import 'package:intl/intl.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
@@ -18,6 +20,7 @@ import 'package:violet/database/query.dart';
 import 'package:violet/locale/locale.dart';
 import 'package:violet/log/log.dart';
 import 'package:violet/pages/database_download/decompress.dart';
+import 'package:violet/platform/misc.dart';
 import 'package:violet/settings/settings.dart';
 import 'package:violet/variables.dart';
 import 'package:violet/version/sync.dart';
@@ -35,16 +38,18 @@ class DataBaseDownloadPage extends StatefulWidget {
   }) : super(key: key);
 
   @override
-  State<DataBaseDownloadPage> createState() => DataBaseDownloadPagepState();
+  State<DataBaseDownloadPage> createState() => DataBaseDownloadPageState();
 }
 
-class DataBaseDownloadPagepState extends State<DataBaseDownloadPage> {
+class DataBaseDownloadPageState extends State<DataBaseDownloadPage> {
   bool downloading = false;
   var baseString = '';
   var progressString = '';
   var downString = '';
   var speedString = '';
 
+  var _showCloseAppButton = false;
+
   @override
   void initState() {
     super.initState();
@@ -95,7 +100,8 @@ class DataBaseDownloadPagepState extends State<DataBaseDownloadPage> {
       Timer timer = Timer.periodic(
           const Duration(seconds: 1),
           (Timer timer) => setState(() {
-                speedString = '${tlatest / 1024} KB/S';
+                final speed = tlatest / 1024;
+                speedString = '${_formatNumberWithComma(speed)} KB/s';
                 tlatest = tnu;
                 tnu = 0;
               }));
@@ -113,8 +119,10 @@ class DataBaseDownloadPagepState extends State<DataBaseDownloadPage> {
         setState(
           () {
             downloading = true;
-            progressString = '${((rec / total) * 100).toStringAsFixed(0)}%';
-            downString = '[${numberWithComma(rec)}/${numberWithComma(total)}]';
+            final progressPercent = (rec / total) * 100;
+            progressString = '${_formatNumberWithComma(progressPercent)}%';
+            downString =
+                '[${_formatNumberWithComma(rec)}/${_formatNumberWithComma(total)}]';
           },
         );
       });
@@ -163,6 +171,7 @@ class DataBaseDownloadPagepState extends State<DataBaseDownloadPage> {
       } else {
         setState(() {
           baseString = Translations.instance!.trans('dbdcomplete');
+          _showCloseAppButton = true;
         });
       }
 
@@ -194,7 +203,8 @@ class DataBaseDownloadPagepState extends State<DataBaseDownloadPage> {
       Timer timer = Timer.periodic(
           const Duration(seconds: 1),
           (Timer timer) => setState(() {
-                speedString = '${tlatest / 1024} KB/S';
+                final speed = tlatest / 1024;
+                speedString = '${_formatNumberWithComma(speed)} KB/s';
                 tlatest = tnu;
                 tnu = 0;
               }));
@@ -212,8 +222,10 @@ class DataBaseDownloadPagepState extends State<DataBaseDownloadPage> {
         setState(
           () {
             downloading = true;
-            progressString = '${((rec / total) * 100).toStringAsFixed(0)}%';
-            downString = '[${numberWithComma(rec)}/${numberWithComma(total)}]';
+            final progressPercent = (rec / total) * 100;
+            progressString = '${_formatNumberWithComma(progressPercent)}%';
+            downString =
+                '[${_formatNumberWithComma(rec)}/${_formatNumberWithComma(total)}]';
           },
         );
       });
@@ -239,6 +251,7 @@ class DataBaseDownloadPagepState extends State<DataBaseDownloadPage> {
       } else {
         setState(() {
           baseString = Translations.instance!.trans('dbdcomplete');
+          _showCloseAppButton = true;
         });
       }
 
@@ -486,6 +499,7 @@ class DataBaseDownloadPagepState extends State<DataBaseDownloadPage> {
 
         setState(() {
           baseString = Translations.instance!.trans('dbdcomplete');
+          _showCloseAppButton = true;
         });
         break;
       }
@@ -493,8 +507,20 @@ class DataBaseDownloadPagepState extends State<DataBaseDownloadPage> {
     }
   }
 
-  String numberWithComma(int param) {
-    return NumberFormat('###,###,###,###').format(param).replaceAll(' ', '');
+  static final _commaFormatter = NumberFormat('#,###.#');
+
+  String _formatNumberWithComma(num param) {
+    return _commaFormatter.format(param).replaceAll(' ', '');
+  }
+
+  Future<void> _exitApplication() async {
+    if (Platform.isAndroid) {
+      await PlatformMiscMethods.instance.finishMainActivity();
+    } else if (Platform.isIOS) {
+      exit(0);
+    } else {
+      ServicesBinding.instance.exitApplication(AppExitType.required);
+    }
   }
 
   @override
@@ -543,7 +569,19 @@ class DataBaseDownloadPagepState extends State<DataBaseDownloadPage> {
                   ),
                 ),
               )
-            : Text(baseString),
+            : Column(
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Text(baseString),
+                  if (_showCloseAppButton) ...[
+                    const SizedBox(height: 32.0),
+                    ElevatedButton(
+                      onPressed: _exitApplication,
+                      child: Text(Translations.of(context).trans('exitTheApp')),
+                    ),
+                  ],
+                ],
+              ),
       ),
     );
   }
diff --git a/lib/platform/misc.dart b/lib/platform/misc.dart
new file mode 100644
index 000000000..886c33a7c
--- /dev/null
+++ b/lib/platform/misc.dart
@@ -0,0 +1,19 @@
+import 'dart:io';
+
+import 'package:flutter/services.dart';
+
+class PlatformMiscMethods {
+  const PlatformMiscMethods._();
+
+  static const instance = PlatformMiscMethods._();
+
+  final _methodChannel = const MethodChannel('xyz.project.violet/misc');
+
+  Future<void> finishMainActivity() async {
+    if (!Platform.isAndroid) {
+      throw UnsupportedError('Android only');
+    }
+
+    await _methodChannel.invokeMethod('finishMainActivity');
+  }
+}