I hear you, @PBJ10. I appreciate your input between QuickBooks Desktop (QBDT) and QuickBooks Online (QBO) reporting features.

While I can't provide specific formulas and a particular name for the third-party app, I can still share guidance to accomplish your goal of creating the Average Days to Pay Report as in QBDT.

It's correct that manually calculating the average number of days each customer takes to pay their invoices should involve data on the payment date and the corresponding invoice. The closest report we can generate in QBO is the Invoices and Received Payments report. Then, customize the report to show the invoice due date. Here's how:

1. Go to Reports. Then, type in "Invoices and Received Payments," and select the report.
2. Choose the Report period. Then, click on Customize.
3. Select Change columns.
4. Place a checkmark for the Due date column.
5. Hit Run report.
6. Click on the Export icon.

In your Excel, you can consider organizing your data to show the Invoice Due Date, Payment Date, and Customer. Then, another column to calculate the difference between Payment Date and Invoice Due Date.

Since this involves manual calculation, let me suggest keywords to help find a third-party app in your QBO. Here's how:

1. Go to Apps in your QBO account.
2. Click on Find apps.
3. In the search bar, type keywords like "Advanced Reporting" or "Financial Reporting.
4. Check the Overview or Review tabs for a summary of what the app offers.
   

Also, if you're considering switching from QBO back to QBDT, please refer to this article: Move data from QuickBooks Online to QuickBooks Desktop.

It's important that the software accommodates various business needs, and your experience highlights where it needs to improve. I still encourage sending feedback to our product engineers to consider adding this report in future updates.

1. Go to the Gear icon.
2. Select Feedback.
3. Enter your comments or product suggestions.

To get guidance on scheduling your sales reports, let me add this article as a future reference: Set schedule and email information for a memorized report.

We'll be here in the Community if you have further questions about generating sales reports in QBO. We'll do our best to assist. Take care.