Do smartphone functions still work in other planets?

If you were to bring an iPhone off to another planet, would you be able to use the camera, compass, watch, and notes on there? If there was no charger, would the phone already be out of battery by the time you get there? What about overheating or radiowaves and stuff like that?

What would you bring with you to an exoplanet to discover life?

You are stranded on an exoplanet and are on a mission to discover life. Out of all these 10 equipments: mirror, flashlight, iphone x, compass, notebook, rope, sandals, camera, watch, magnifying glass; you can only bring 3. What would be the 3 that you take with you to explore?