I accidently deleted the joist app and now when I try to add it back it won't show up in the search, does anyone know how to fix this?

Hello, nathan.  

Thank you for posting in the Community. I want to ensure you can integrate the Joist app into QuickBooks again. As per checking Joist app is no longer supported in QBO. 

I suggest contacting the Joist support team, as they have the tools to check which similar app is compatible with QuickBooks. 

You may want to check this article about the apps available in QuickBooks Online: 3rd party software that works with QuickBooks. 

Let me know if you have additional questions about the mobile app. Just leave a comment below, and I'll get back to you.