You can extend capabilities of your PowerApps App by connecting to FLOW. At some point you might find that available connectors in PowerApps are not enough to fulfill you requirements. And FLOW has many more connectors and actions, which you were looking for.

FLOW can be triggered from PowerApps to perform read or write operation on your data source. When its read operation you need to respond back from FLOW to PowerApps, doesnt matter if its single value or tabular data. In this article video we will see how to send back data from FLOW to PowerApps, and how to process such data in PowerApps.