Your 1 April plan, per app

Load the EWS usage report export from your tenant. It is read here, in your browser, and never uploaded. You see every app in it for free; the tenant plan adds each vendor's migration status, the allow-list check and the outputs.

1. Your usage report

Microsoft 365 admin center: Reports, Usage, Exchange, the EWS usage tab, then Export. It downloads a CSV.

2. Your EWS allow list (optional)

In Exchange Online PowerShell, run this and paste what it prints. Only the application IDs in it are read.

Get-OrganizationConfig -RetrieveEwsOperationAccessPolicy | Format-List EwsAllowedAppIDs Copy