Saw on another thread: Transiting in LAX and thoughts on United (geekzone.co.nz) people mentioning this app for getting through customs faster: Mobile Passport Control (MPC) | U.S. Customs and Border Protection (cbp.gov)
Looks great, and as always a stunning hidden gem surfaced by geekzone.
Anyone used it at Houston? When I go to use it, it says Terminal E supported - AirNZ lands at Terminal D.
When I look at the Houston Airport map it looks like D and E all feed into the same immigration/customs area (right hand side of the map): IAH (fly2houston.com)