NRF52 BLE Serial to iOS

I am completely new to working with BT, especially the idea of mating it with iOS. As I see it, my idea is quite simple, but I know I need to start with the hardware, then get the app coded to it. I am looking to build the attached. It is for a specific application, so need to function exactly as shown. I have tried to look around and seen some good guides for serial BLE adapters, but I need to make sure I have this right for the intended use. I have spoken to a couple of companies and gotten OTT quotes just to design the hardware, so thought I'd investigate myself. Any and all help would be greatly appreciated.

I already have an idea for the battery pack, but adding a charging capabilty would be very handy.