Ios App Crashes *FIXED*

So I have 2 questions
When I try to press the arrow on my ios app to go to “reflash tinker” it crashes
(Spark core app)
How can you flash a program from particle build to your spark core without removing tinker?

You can’t. Tinker is just a program much like anything you’d write yourself. Upon flashing your own app, you overwrite it, thus making it unavailable. Personally I don’t really see the point in having Tinker if you’re going to flash your own firmware, but each to his own.
If you want to maintain Tinker functionality, you’ll have to incorporate the relevant code in your own firmware. You can check the Tinker code in the docs.