diff --git a/browser/users/UserSystem.ts b/browser/users/UserSystem.ts
index 647514f..6f1014a 100644
--- a/browser/users/UserSystem.ts
+++ b/browser/users/UserSystem.ts
@@ -60,6 +60,23 @@ export class SessionData
   renewal:string;
 }
 
+export class UserAppData
+{
+  token:string;
+  appID:string;
+}
+
+export class UserSavingAppData extends UserAppData
+{
+  appData:any;
+}
+
+export class UserTaskDeletionData extends UserAppData
+{
+  taskID:string;
+}
+
+
 export class UserSystem
 {
   static productionURL = "https://backend.rokojori.com:1712";
@@ -283,4 +300,78 @@ export class UserSystem
 
     return Promise.resolve( MessageTypes.Error !== result.type );
   }
+
+  protected _getAppsURL( name:string )
+  {
+    return this.url + "/apps" + name;
+  }
+
+  async canUseApp( appID:string ):Promise<boolean>
+  {
+
+    let url = this._getAppsURL( "/can-use" );
+
+    let input = { token:this.sessionToken, appID: appID };
+
+    let result = await Request.post<UserAppData,Message>( url, input ); 
+
+    if ( MessageTypes.Error == result.type )
+    {
+      console.log( result );
+      return Promise.resolve( false );
+    }
+
+    return Promise.resolve( true );
+  }
+
+  async loadAppData<T>( appID:string ):Promise<T>
+  {
+    let url = this._getAppsURL( "/load" );
+
+    let input = { token:this.sessionToken, appID: appID };
+
+    let result = await Request.post<UserAppData,DataMessage<T>>( url, input ); 
+
+    if ( MessageTypes.Error == result.type )
+    {
+      console.log( result );
+      return Promise.resolve( null );
+    }
+
+    return Promise.resolve( result.data );
+  }
+
+  async saveAppData<T>( appID:string, data:T ):Promise<boolean>
+  {
+    let url = this._getAppsURL( "/save" );
+
+    let input = { token:this.sessionToken, appID: appID, appData:data };
+
+    let result = await Request.post<UserSavingAppData,DataMessage<T>>( url, input ); 
+
+    if ( MessageTypes.Error == result.type )
+    {
+      console.log( result );
+      return Promise.resolve( false );
+    }
+
+    return Promise.resolve( true );
+  }
+
+  async deleteAppTask( appID:string, taskID:string ):Promise<boolean>
+  {
+    let url = this._getAppsURL( "/delete-task" );
+
+    let input = { token:this.sessionToken, appID: appID, taskID:taskID };
+
+    let result = await Request.post<UserTaskDeletionData,Message>( url, input ); 
+
+    if ( MessageTypes.Error == result.type )
+    {
+      console.log( result );
+      return Promise.resolve( false );
+    }
+
+    return Promise.resolve( true );
+  }
 }
\ No newline at end of file