We have made a number of products, Jam/MiC/Jam96k/MiC96k, which are Input Only devices for iOS.
When Apple started removing the headphone jacks from the iPhones this created a minor issue for users who got a new iPhone, and could no longer connect headphones to monitor their input with Jam/MiC/Jam96k/MiC96k.
You can use the Apple Lightning Dock to connect both your Jam/MiC/Jam96k/MiC96k and your Headphones, to your iPhone, at the same time.
You can also look into our newer devices we made after these new iPhones came out, which now have headphones jacks built in, with Low Latency Monitoring. These are MiC Plus, Jam Plus, and now HypeMiC!