Use IOS app: HM10 Bluetooth Serial Lite
Software: SerialPort
You can connect the HM10 bluetooth module with USB to TTL module, then you can send message from your iphone to SerialPost windows
Connection:
HM-10 usb to TTL module
VCC 5V
GND GND
TXD RXD
RXD TXD
Open Bluetooth on iphone , ipen HM10 Bluetooth Serial Lite APP and software SerialPort, you can type message in the APP, then the message will be send to SerialPort windows