Classic trainer and using only iPhone to display/play. Obviously will need a bluetooth setup. What exactly do I need to get? Just a BT speed/cadence sensor?? Any recommended brand?
And what is the Zwift Companion app? Do I need this AND the Zwift app?
Thanks for any direction!
Hi Kathy welcome to Zwift.
Yes you need a bluetooth Speed sensor. I don’t know of recommended sensors, but I would say read some reviews before buying.
Below id a few links that may be helpful.
https://support.zwift.com/en_us/wheel-on-trainers-r1B5nQWxS
the companion app is handy to have, you can see when your friends are zwifting and see what events is coming up.
In my experience, you can’t go wrong with Wahoo sensors.
Thanks to you both! I’ve got a Wahoo sensor on its way. I’m actually gifting my husband with a 3 month membership and want to make sure he’ll have everything to get started easily (we can be our own controversial ad like Peloton perhaps, haha!).
Let us know if you have any other questions. Or need more Christmas ideas. 
A gift of Zwift is a gift of Love.