Also the smarten IT relays which are on the official compatibility list will act as zigbee repeaters if you have a place to use those.
But there are lots of community member successful using zigbee bulbs as repeaters. I’m not sure what Luke’s issues were, “all home automation is local.”
And The Iris Smart Plug is a Zigbee pocket socket that also has a Zwave repeater in it. Which is weird, but it works and there is already a community created device type for it:
Remember that no matter what device you use as a repeater, you have to do a network heal after you add the repeater or the sensor won’t know that it’s there and won’t use it.