I want to confirm if Office 365 E3 Subscription offers full capabilities of Power Apps and Power Automate. We have proposed our client to develop solution on Power Apps and Power Automate and interested to know if there are per user or per app or per flow limitation in E3 subscription.
Office 365 E3 contains what Microsoft refers to as a "seeded" license for Power Apps and Power Automate. This means anyone can make use of standard functionality, possibly with certain limitations. Once advanced functionality is needed, you will need to acquire a premium license for the specific Power Platform services that are being used. Examples here are the use of Premium Connectors or using Dataverse (CDS) storage.
Power Platform licensing can be very complex, and I would recommend to go over the PDF below.