diff --git a/lib/webdriveragent.js b/lib/webdriveragent.js
index fdae2bff6..a80909954 100644
--- a/lib/webdriveragent.js
+++ b/lib/webdriveragent.js
@@ -301,9 +301,19 @@ class WebDriverAgent {
       xctestEnv.MJPEG_SERVER_PORT = this.mjpegServerPort;
     }
     this.log.info('Launching WebDriverAgent on the device without xcodebuild');
-    this.xctestApiClient = new Xctest(this.device.udid, this.bundleIdForXctest, null, {env: xctestEnv});
-
-    await this.xctestApiClient.start();
+    if (this.isRealDevice) {
+      this.xctestApiClient = new Xctest(this.device.udid, this.bundleIdForXctest, null, {env: xctestEnv});
+      await this.xctestApiClient.start();
+    } else {
+      await this.device.simctl.exec('launch', {
+        args: [
+          '--terminate-running-process',
+          this.device.udid,
+          this.bundleIdForXctest,
+        ],
+        env: xctestEnv,
+      });
+    }
 
     this.setupProxies(sessionId);
     const status = await this.getStatus();
@@ -343,10 +353,7 @@ class WebDriverAgent {
     }
 
     if (this.usePreinstalledWDA) {
-      if (this.isRealDevice) {
-        return await this.launchWithPreinstalledWDA(sessionId);
-      }
-      throw new Error('usePreinstalledWDA is available only for a real device.');
+      return await this.launchWithPreinstalledWDA(sessionId);
     }
 
     this.log.info('Launching WebDriverAgent on the device');
@@ -460,10 +467,16 @@ class WebDriverAgent {
 
   async quit () {
     if (this.usePreinstalledWDA) {
+      this.log.info('Stopping the XCTest session');
       if (this.xctestApiClient) {
-        this.log.info('Stopping the XCTest session');
         this.xctestApiClient.stop();
         this.xctestApiClient = null;
+      } else {
+        try {
+          await this.device.simctl.terminateApp(this.bundleIdForXctest);
+        } catch (e) {
+          this.log.warn(e.message);
+        }
       }
     } else if (!this.args.webDriverAgentUrl) {
       this.log.info('Shutting down sub-processes');