This is not a standalone app, but a library to work in conjunction with other apps, like: https://github.com/jtrotsky/spate (Sales report export) https://github.com/jtrotsky/so-report (Consignment report export)
Please use the above as an example of how to use the library.
DISCLAIMER: This is by no means endorsed by Vend, and is a library built for Vend's experimental 2.x API so should be used with caution.