If the console on the Life Fitness IC6, IC7, or IC8 is the latest generation (WATTRATE TFT COMPUTER 2.0) then it has Bluetooth 5.0 and is ‘open’ and can connect to any app, including Zwift. This console was introduced on 2020 models. The consoles on earlier models have bluetooth that is ‘locked’ so that only the ICG app can share data. However, earlier models might be upgradable to the newer console. From Life Fitness tech support: “The TFT 2.0 console requires a power module version V59 or greater to work. The power module version can be found in the settings menu. Once your power module has been confirmed to match with the requirement, use the part number 320-00-00016-01 (price $347.12 retail) to purchase a TFT 2.0 retrofit kit.”
I have an IC7 with a manufacture date of December 2018 and I was able to successfully upgrade my console. I am now able to use my IC7 with Zwift running on an Apple TV 4K and it works beautifully. The new console is much more responsive and pairs extremely quickly, every time (including with the ICG app, with which the previous console would frequently have problems). It has a few other improvements over the previous version that you can read about here. I believe that it is the same console for models IC6, IC7, and IC8 – but it will only display the left/right leg power diagram if used with an IC8. I would confirm that with LF support before attempting to upgrade an IC8 if that feature is important to you.
I believe that ANT+ is ‘open,’ even on the old consoles. But, to make recent (lightning connector) iOS devices capable of receiving ANT+ requires stringing together a couple of adapters that are no longer being made and might be very difficult to find and, TBH, is a bit of a kludge. Another possibility is to use the ‘CABLE’ device made by North Pole Engineering that will translate ANT+ signals to Bluetooth. This device is currently available and is substantially cheaper than upgrading your console.
Connecting these older LifeFitness bikes to a PC or Mac running Zwift should not be too difficult. One would only have to purchase a USB to ANT+ dongle. Alternatively, to connect via bluetooth, you could use the previously mentioned CABLE device (or upgrade to TFT 2.0 console).
Addendum: Forgot about the Viiiiva Heart Rate Monitor. It has an ANT+ to Bluetooth bridge feature that works in essentially the same way as the NPE CABLE device. AFAIK, that sums up every possible way that you can connect your LF IC6, IC7, or IC8 to Zwift on iOS, tvOS, PC, or Mac. It is my understanding that there are some Android devices with built-in ANT+ receivers, but it is not common.