At the Augusto C. Sandino International Airport (the airport in Managua, Nicaragua), I have heard there is a VIP service you can pay for, where an agent will meet you when disembarking from the plane and guide you through the immigration and customs process, or somehow make it easier. How exactly does this VIP service work? What does it cost, how do you sign up, and what does it include?
However the link they provide does no longer work.
An English page on the Airport site talks a bit about the VIP lounge but not about the whole service. The Spanish version of the page mentions the $30 again but doesn't explain all the services. It does however list a phone number and email address for reservations. You can try to email them and ask for details.
There is also some talk about the service on the Nicaragua Living site, but it doesn't really answer your question.
After emailing the address mentioned by Peter Hahndorf in his answer (email@example.com), I learned the following from "VIP Shift Managers" on duty who answered the emails: