YML (Yandex Market Language) — is XML file with products for Yandex.Market. Not to be confused with YAML files, which also have .yml extension.
This module provide API for developers to generate product yml file. Module doesn't contain any administrative interface.
Official validator — don't forget to change tab to Market.
This module will not be ported to Drupal 7 because of it's architecture. Module is build on OOP, services and annotations (some dependencies from doctrine from Drupal 8 core). I recommend don't waste your time and use already working module for it: Yandex Market YML Generator API.