Groestlcoin is a cryptocurrency created in 2014 by a team of developers from across the globe. The team remains anonymous on the internet but regularly visits blockchain events (meetup, conventions ...). The aim of the project is to offer a currency that can be used in everyday life (ordering a taxi, paying in shops, etc.). GRS transactions are extremely fast and the fees are low.
The GRS takes its name from the algorithm it uses, "Grøstl". Groestlcoin is a cryptocurrency that can be mined easily with a GPU or CPU. GRSPay is an open-source payment software allowing to receive payments in Groestlcoin without fees and without intermediary. So, when making a payment, the GRS go directly to your wallet. This software is on and protects your data, in fact your private keys are never downloaded to the server. There is no reuse of address because each invoice generates a new derivative of your xpubkey or zpubkey.
The software will soon support Lightning Network, it already supports SegWit. It is possible to run GRSPay on your own server or use a Groestlcoin host server. Hosting the solution allows you to attach an unlimited number of stores but also to become a host for others.