What does the "Use for Development" button in Xcode Organizer do to an iOS device?

Question

When selecting an iOS device and clicking the "Use for Development" button in Xcode organizer, what does it change on the device (iPhone or iPad)?

Are there any debugging symbols installed or some sort of profilers or loggers?

Does this mode affect device performance or battery life while being "used for development"?

Answer 1

It installs a development profile certificate on your device. Code signed by these certificate will be accepted to run on the device.

Answer 2

From my experience, the practical consequences of turning on a device for development are an increase of levels of logged data and access to these logs. (I'm not sure if logs are activated for all apps or just those you develop yourself.)

This extra logging activity might have a storage impact and an impact on energy consumed too but as you're most of the time plugged in a machine running XCode when you test the applications you develop, I never saw any impact on the battery life when I switched back to be a regular user of my device (as opposed to a developer user).