Testnet exchange: Template solution for exchanges consits of 2 pieces 1) the Grin Wallet APIs for Grin community wallet developers via a JSON-RPC interface 2) areference command-line wallet, which provides a baseline wallet for Grin and demonstrates how the wallet APIs should be called.
Vault713 - Grinbox: (last commit 2019) - Grinbox provides a simple way for parties to exchange transaction slates, 3rd party as transaction buffer/intermediate.
GrinGots wizarding bank: (last commits in 2019), Gringotts is a CLI app that you can use to send and receive grins instantly using one of the available backends for communication.
Grin documentation: Your journey down the rabit hole starts here! Learn about where Grin comes from, Mimble Wimble, Pederson commitments, Eliptic Curve cryptography as well as practical tutorails on how to install and use the grin node software and grin-wallet.
Grin Papyrus: Collection of important documents and links related to the development of GRIN. Find back everything, the early steps towards Grin in 2016, launch in 2019 and everything that happened after
Grinventions Telegram channel: Innovative inventions for the grin cryptocurrency. Also discusses building the MimbleWimble Python implementatoin and quantum computing basic in Python