Why can I no longer make an invoice? There is no longer a fast-tab for invoices in the app.

Hello jwdcontracting, 

It's good to have you join the QuickBooks Community. I'll be happy to provide the info you need so you can send invoices to your customers with ease. 

Based on what you've described, I highly recommend uninstalling and reinstalling the app. This is a great way to troubleshoot issues that may be affecting the app. By reinstalling the app, this ensures you're on the latest version of the mobile app. 

Give this a try and let me know if you're able to create invoices. I'll be one message away.