If the Direct Express app is not opening on your iPhone, follow these steps to troubleshoot and resolve the issue:

1. Restart Your iPhone
- Hold down the power button until you see "slide to power off".
- Slide to turn off your device.
- After a few seconds, turn your iPhone back on by holding the power button again.

2. Update the Direct Express App
- Open the App Store on your iPhone.
- Tap on your profile icon in the top right corner.
- Scroll down to see if the Direct Express app has an available update.
- If an update is available, tap "Update" next to the app. This can often fix bugs that affect app performance - learn more.

3. Clear App Cache
- Unfortunately, iOS does not have a direct method to clear app cache. However, you can remove and reinstall the app. This effectively resets it and might resolve opening issues.
- Press and hold the Direct Express app icon until options appear.
- Select "Remove App", then confirm.
- Go to the App Store and reinstall the Direct Express app - learn more.

4. Check for iOS Updates
- Go to "Settings" > "General" > "Software Update".
- If an update is available, download and install it to ensure compatibility with the app - learn more.

5. Ensure Good Internet Connection
- Verify that your Wi-Fi or mobile data connection is stable. A poor connection may prevent the app from opening. Try switching between Wi-Fi and mobile data to see if there’s a difference.

6. Contact Direct Express Support
- If the issue persists, consider contacting Direct Express customer support for further assistance. You can find contact information on the back of your Direct Express card or in the app's support section - learn more.

7. Check for Server Issues
- Sometimes, the app may not work due to server maintenance or outages. You can check community forums or social media for reports about known issues affecting the app at that time - learn more.

Following these steps should help you get the Direct Express app working on your iPhone again. If none of these solutions work, further technical support may be necessary.