The new JSON function in PowerApps is great and we have been using it extensively. Another great addition would be to parse JSON directly in PowerApps. If PowerApps receives a stringified JSON string, it should be able to easily Parse this and use this data in the app, to write it into a collection, variable or whatever.
We have been using the HTTP response in flow to return dynamic data to PowerApps, but seeing that this is now longer included in the Office 365 entitlement and that normal Respond To PowerApps Flow action not supporting Arrays or JSON, this request is quite urgent.
Please let us know if you have any questions or suggestions.