Hello there, kochumai. Glad to have you here.
Yes, QuickBooks Online Essentials allows app integration. But, some apps require to have QuickBooks Online Plus. If you're trying to look for a third-party application, you can go directly to this link: https://quickbooks.intuit.com/app/apps/home/. Once you get there, you can then enter a keyword of the app. Then, you can review the benefits of the app and other user's feedback from there.
Also, you may want to check these articles for additional reference about handling data in QBO:
Feel free to comment again if you have other concerns with QuickBooks. I'd be glad to help you figure them out. Take care always and stay safe.
