I'm developing an iOS app that should communicate with a Raspberry Pi to send and receive simple data. I've researched a little bit and found out that making this connection using BLE would be the correct way, as my project cannot depend on network signal (in this case I could use MQTT or some socket approach).
My doubt is, which BLE module for raspberry would work with iOS and Core Bluetooth framework? Would HM-10 work?
The Raspberry Pi 4b is capable of Bluetooth 5 and therefore capable of Bluetooth Low Energy. There is no need for additional hardware. There is a great answer below this question by @ukBaz regarding the usage of BLE and the D-Bus API on a Raspberry Pi