QB app not working

We can perform some troubleshooting steps as accumulated cache in QuickBooks can affect the software's performance, r-c-fletcher.
 

The data stored on your device may affect its functionality and display. Follow these steps to refresh it without deleting your app's documents and data:
 

1. Go to Settings, then tap General.
2. Choose iPhone Storage, then click the QuickBooks Online app.
3. Select Offload App.
    

If the issue continues, I suggest uninstalling and reinstalling it. This will help ensure that you have the most current version of the software.
 

Alternatively, you can access your QBO account via a web browser on your mobile device. This method offers full functionality and continuous access to your financial tools.
 

Check out this link to help you manage your account in QuickBooks: Get started with QuickBooks Online. You’ll also find links to other how-to articles so you can get your business up and running.
 

If you have other concerns in the future, use the Reply button below or post directly on the Community page.