I use a Roland GO:Mixer. Works great.
Also, the Behringer UCA222 is a tiny bus driven interface with stereo inputs and monitoring ability. Super cheap. You will need the apple usb “camera” adapter but I can verify it works, before I owned the Roland, I used this.
Wireless card reader by Apotop. Plug the op1 into the reader. Connect ur phone the the readers wifi hotspot. Open up the readers app on ur phone. Put the op1 into disk mode. You can now access the entire op1 file structure and download to ur phone.