It's good to see you posting today. I'm happy to answer your question about using an app, KS1966.
You may have the app on my computer and delete the application that is stored on my C: Drive. Yes, you can go to the intuit site to log in to safely get rid of the app on my computer. You can also access your QuickBooks Online company using a browser on your computer or your mobile devices. However, if you want a quicker way to access your account, you can use an app. The app is not necessary, but it's more convenient.
I'm adding these articles for your additional reference:
Additionally, feel free to browse this link here in case you need help with other tasks in QBO. It has our general topics with articles that'll guide you along the way.
Please know that you're always welcome to comment below if you have other concerns or follow-up inquiries about managing your business in QBO. I'm just around to help. Have a great day ahead.