My BLE Device is not shown in iOS Bluetooth Manager when trying to connect

Answer

iOS devices will not pair with BLE devices unless one of the device's characteristics specifies that encryption is required. Apps need to provide their own UI for the user to discover and select the BLE peripheral they want to work with, this is because the app knows what service(s) are required for the app while iOS Bluetooth settings does not. Even when pairing of BLE devices is performed it is still initiated through the app. Bluetooth settings is used to "forget" the device (remove the stored encryption keys). However, it seems that iOS does list BLE devices when they advertise some of the BT SIG adopted services such as the Heart Rate service. By advertising this service you can get your device visible in the Bluetooth Settings page..