diff --git a/quasar.conf.js b/quasar.conf.js
index 34df237c..ce491369 100644
--- a/quasar.conf.js
+++ b/quasar.conf.js
@@ -222,7 +222,7 @@ module.exports = configure(function (ctx) {
       builder: {
         // https://www.electron.build/configuration/configuration
         appId: 'dev.paperlib.app',
-        productName: 'paperlib',
+        productName: 'Paperlib',
         publish: [
           {
             provider: 'generic',
diff --git a/quasar.conf.mac.js b/quasar.conf.mac.js
index 34df237c..ce491369 100644
--- a/quasar.conf.mac.js
+++ b/quasar.conf.mac.js
@@ -222,7 +222,7 @@ module.exports = configure(function (ctx) {
       builder: {
         // https://www.electron.build/configuration/configuration
         appId: 'dev.paperlib.app',
-        productName: 'paperlib',
+        productName: 'Paperlib',
         publish: [
           {
             provider: 'generic',
diff --git a/quasar.conf.win.js b/quasar.conf.win.js
index e87f51fb..adc18a1c 100644
--- a/quasar.conf.win.js
+++ b/quasar.conf.win.js
@@ -222,7 +222,7 @@ module.exports = configure(function (ctx) {
       builder: {
         // https://www.electron.build/configuration/configuration
         appId: 'dev.paperlib.app',
-        productName: 'paperlib',
+        productName: 'Paperlib',
         publish: [
           {
             provider: 'generic',
diff --git a/src-electron/electron-main.js b/src-electron/electron-main.js
index eb44ae44..d5e292d1 100644
--- a/src-electron/electron-main.js
+++ b/src-electron/electron-main.js
@@ -67,6 +67,14 @@ function createWindow() {
     mainWindow = null;
   });
 
+  mainWindow.on('blur', () => {
+    mainWindow.webContents.send('window-lost-focus');
+  });
+
+  mainWindow.on('focus', () => {
+    mainWindow.webContents.send('window-gained-focus');
+  });
+
   setMainMenu();
 }
 
diff --git a/src/css/preference-view.scss b/src/css/preference-view.scss
index c8a55403..8dff0928 100644
--- a/src/css/preference-view.scss
+++ b/src/css/preference-view.scss
@@ -1,6 +1,6 @@
 .preference-view {
   width: 800px;
-  height: 420px;
+  min-height: 450px;
   background-color: var(--q-bg-primary) !important;
   color: var(--q-text) !important;
 }
diff --git a/src/interactors/entity-interactor.ts b/src/interactors/entity-interactor.ts
index 0652f2e0..3c6cd433 100644
--- a/src/interactors/entity-interactor.ts
+++ b/src/interactors/entity-interactor.ts
@@ -358,6 +358,27 @@ export class EntityInteractor {
     this.sharedState.set('viewState.realmReinited', new Date().getTime());
   }
 
+  pauseSync() {
+    this.scheduler.removeById('pauseSync');
+    const task = new Task('pauseSync', () => {
+      void this.dbRepository.pauseSync();
+      this.scheduler.removeById('pauseSync');
+    });
+
+    const job = new SimpleIntervalJob(
+      { seconds: 36, runImmediately: false },
+      task,
+      'pauseSync'
+    );
+
+    this.scheduler.addSimpleIntervalJob(job);
+  }
+
+  resumeSync() {
+    this.scheduler.removeById('pauseSync');
+    void this.dbRepository.resumeSync();
+  }
+
   // ============================================================
   initFileRepository() {
     if (this.preference.get('syncFileStorage') === 'webdav') {
diff --git a/src/pages/Index.vue b/src/pages/Index.vue
index ce99add2..7acb89c7 100644
--- a/src/pages/Index.vue
+++ b/src/pages/Index.vue
@@ -177,6 +177,14 @@ export default defineComponent({
       void window.entityInteractor.addFromPlugin([message as string]);
     });
 
+    window.systemInteractor.registerSignal('window-lost-focus', (_event, _message) => {
+      void window.entityInteractor.pauseSync();
+    });
+
+    window.systemInteractor.registerSignal('window-gained-focus', (_event, _message) => {
+      void window.entityInteractor.resumeSync();
+    });
+
     window.systemInteractor.registerState('viewState.realmReinited', (_event, _message) => {
       void (async () => {
         await reloadEntities();
diff --git a/src/pages/preference_view/components/CloudTab.vue b/src/pages/preference_view/components/CloudTab.vue
index bc64f4f7..f9a431de 100644
--- a/src/pages/preference_view/components/CloudTab.vue
+++ b/src/pages/preference_view/components/CloudTab.vue
@@ -1,5 +1,32 @@
 <template>
     <q-tab-panel name="cloud" class="preference-tab">
+        <div class="row setting-title" style="text-align: left !important">
+            <span style="font-weight: 500">
+                Cloud Backend
+            </span>
+        </div>
+        <div class="row setting-content q-mb-md">
+            <div class="col-2">
+                <q-radio v-model="syncCloudBackend" val="official" label="Official" size="xs" @update:model-value="(value) => onUpdate('syncCloudBackend', value)" />
+            </div>
+            <div class="col-4">
+                <q-radio class='q-ml-sm' v-model="syncCloudBackend" val="custom-atlas" label="Custom Mongodb Atlas" size="xs" @update:model-value="(value) => onUpdate('syncCloudBackend', value)" />
+            </div>
+            <div class="col-4 q-mt-xs" v-if="syncCloudBackend === 'custom-atlas'">
+                <div class="radius-border setting-content preference-input" >
+                    <q-input
+                        borderless
+                        v-model="syncAPPID"
+                        placeholder="Mongodb Atlas APP ID"
+                        dense
+                        style="max-height: 22px"
+                        @update:model-value="(value) => onUpdate('syncAPPID', value)"
+                    />
+                </div>
+            </div>
+        </div>
+
+
         <div class="row setting-title q-mb-xs" style="text-align: left !important">
             <span style="font-weight: 500">
                 Cloud Account
@@ -53,7 +80,7 @@
                     v-if="preference.useSync"
                 />
             </div>
-            <div class="col-1">
+            <div class="col-1" v-if="syncCloudBackend === 'official'">
               <q-btn
                   unelevated
                   no-caps
@@ -190,6 +217,8 @@ export default defineComponent({
     const syncEmail = ref(props.preference.syncEmail);
     const syncPassword = ref('');
     const syncFileStorage = ref(props.preference.syncFileStorage);
+    const syncCloudBackend = ref(props.preference.syncCloudBackend);
+    const syncAPPID = ref(props.preference.syncAPPID);
     const syncFileStorageAvaliable = ref(window.systemInteractor.getState('viewState.syncFileStorageAvaliable') as unknown as boolean);
     const webdavURL = ref(props.preference.webdavURL);
     const webdavUsername = ref(props.preference.webdavUsername);
@@ -245,6 +274,8 @@ export default defineComponent({
       syncEmail,
       syncPassword,
       syncFileStorage,
+      syncCloudBackend,
+      syncAPPID,
       syncFileStorageAvaliable,
       webdavURL,
       webdavUsername,
diff --git a/src/repositories/db-repository/db-init.ts b/src/repositories/db-repository/db-init.ts
index 75c6a0e3..032c014c 100644
--- a/src/repositories/db-repository/db-init.ts
+++ b/src/repositories/db-repository/db-init.ts
@@ -19,6 +19,7 @@ export async function initRealm(this: DBRepository, reinit = false) {
     this._realm = null;
     this.app = null;
     this.cloudConfig = null;
+    this.syncSession = null;
     this.localConfig = null;
     this.entitiesListenerInited = false;
     this.categorizersListenerInited = {
@@ -34,6 +35,7 @@ export async function initRealm(this: DBRepository, reinit = false) {
   if (this.cloudConfig) {
     try {
       this._realm = new Realm(this.cloudConfig);
+      this.syncSession = this._realm.syncSession;
     } catch (err) {
       this.sharedState.set(
         'viewState.alertInformation',
@@ -113,8 +115,15 @@ export async function loginCloud(
 ): Promise<Realm.User | null> {
   if (!this.app) {
     process.chdir(this.sharedState.dbState.defaultPath.value as string);
+
+    let id;
+    if (this.preference.get('syncCloudBackend') === 'official') {
+      id = 'paperlib-iadbj';
+    } else {
+      id = this.preference.get('syncAPPID') as string;
+    }
     this.app = new Realm.App({
-      id: 'paperlib-iadbj',
+      id: id,
     });
   }
 
@@ -160,3 +169,15 @@ export async function logoutCloud(this: DBRepository) {
 
   await this.initRealm(true);
 }
+
+export function pauseSync(this: DBRepository) {
+  if (this.syncSession) {
+    this.syncSession.pause();
+  }
+}
+
+export function resumeSync(this: DBRepository) {
+  if (this.syncSession) {
+    this.syncSession.resume();
+  }
+}
diff --git a/src/repositories/db-repository/db-repository.ts b/src/repositories/db-repository/db-repository.ts
index dbbb0102..62f4d6cc 100644
--- a/src/repositories/db-repository/db-repository.ts
+++ b/src/repositories/db-repository/db-repository.ts
@@ -10,6 +10,8 @@ import {
   initRealm,
   loginCloud,
   logoutCloud,
+  pauseSync,
+  resumeSync,
 } from './db-init';
 import {
   categorizers,
@@ -36,6 +38,8 @@ export class DBRepository {
   cloudConfig: Realm.Configuration | null;
   localConfig: Realm.Configuration | null;
 
+  syncSession: Realm.App.Sync.Session | null = null;
+
   entitiesListenerInited: boolean;
   categorizersListenerInited: Record<string, boolean>;
 
@@ -72,6 +76,8 @@ export class DBRepository {
   loginCloud = loginCloud;
   logoutCloud = logoutCloud;
   migrateLocaltoCloud = migrateLocaltoCloud;
+  pauseSync = pauseSync;
+  resumeSync = resumeSync;
 
   // CRUD Func
   entitiesByIds = entitiesByIds;
diff --git a/src/utils/preference.ts b/src/utils/preference.ts
index 2d0930be..a94a1fca 100644
--- a/src/utils/preference.ts
+++ b/src/utils/preference.ts
@@ -48,6 +48,8 @@ export const defaultPreferences: PreferenceType = {
   exportReplacement: [],
 
   useSync: false,
+  syncCloudBackend: 'official',
+  syncAPPID: '',
   syncAPIKey: '',
   syncEmail: '',