App Data NOT getting displayed as it should on a device

Having IoT connectivity built in to Retool sounds like a good idea.
Definitely deserves a topic of it's own as I would live to dig in to it deeper.
I was imagining borderline of retool would be API connectivity. Maybe webhooks.
And as much as I would want my dash to be super reactive and WebSocket realtimy I'm not sure retool would be able to handle the load.

Meanwhile I'm getting pretty frustrated with preview not reflecting the actual layout of the app.
I don't know how to edit something I can not properly see. Makes me have a phone by that needs retool relaunched to reflect changes. This is too slow to be a long term solution.

Can someone from Retool show me how can I preview my edits on Retool screen so it reflects the way it looks on the phone, please.