Here we provide a little bit of documentation about the asset HZGRP that is implemented on the Horizon platform (as asset ID 7378606282718620840).
HZGRP represents GRPoin, an ancient coin merged-mined alongside BiTCoin, as implemented on the Horizon platform.
The currency consists of only 21,000,000 coins, as it was originally inspired by BiTCoin. Unfortunately we were technically unable to create it as a currency on Horizon so had to create it as an asset. The issuing account created all 21,000,000 so that if all of the coins get transfered to the Horizon platform the platform is ready to handle them all. However, any that remain in the issuing account are taken as not having been issued on the Horizon platform.
Any GRP that have been issued to the Horizon platform are transfered out of the issuing account, so that the amount by which the issuing account is short of 21,000,000 is the number of GRP that has actually been issued onto the Horizon platform.
Some potentially useful tables and plots are online at http://galaxies.mygamesonline.org/digitalisassets.html