Did I buy 4 TS by mistake?

So – bought 4 tentacle sync thinking (based on the tutorial videos) that I’d need 1 per camera.

I own 4 GH5 bodies and a sound devices 633 mixer.

Problem: I can see that the GH5s have a timecode function baked in.

Wouldn’t it make sense to: sync to my mixer, then plug/unplug the ONE tentacle sync to each camera? Or do I still need to record each tentacle to their respective audio tracks?

Bonus question: what’s the ios app for? (I can’t think why i would need this)

Thank you!