Really complicated, and really expensive Swiss Watches are called grand complications based upon strict criteria.
These are often based upon the gravity compensating tourbillon mechanism that isn't strictly needed for a wristwatch but is insanely complicated so people build them to show off their skills as watchmakers.
This is the kind of gadget that gazillionaires with enough taste to avoid diamond encrusted ones buy when they fly into Geneva. They look very James Bond - except that they cost ten times as much as his humble Rolex or Omega, often costing more than $100,000 each.
