Hi,
it is possible.
- Cloud based app. it can use hydra so you can have Delphi host and .NET plugin or .NET host and Delphi plugin. this is a kind of proxy so it should transfer requests from mobile app to desktop app. .NET and Delphi part should use different ports
- Desktop based app that connects to cloud app via http/superhttp (or https/superhttps). it is able to receive events from cloud based app thru firewall
- mobile app.
you can review of solution from Forward traffic between servers. HTTP Chat sample topic. it can be used in cloud app.