Ethereum

about testnets; https://ethereum.stackexchange.com/questions/27048/comparison-of-the-different-testnets

first download geth; https://geth.ethereum.org/downloads/

rinkeby (PoA & stable);

• instructions; https://gist.github.com/cryptogoth/10a98e8078cfd69f7ca892ddbdcf26bc
• geth.exe --rinkeby --cache=4096 --datadir D:\misc\cryptocoins\wallets\ethereum\testnet-rinkeby console

ropsten (PoW & unstable);

• https://github.com/ethereum/ropsten#troubleshooting
• geth.exe --testnet --cache=4096 --datadir D:\misc\cryptocoins\wallets\ethereum\testnet-ropsten --bootnodes "enode://20c9ad97c081d63397d7b685a412227a40e23c8bdc6688c6f37e97cfbc22d2b4d1db1510d8f61e6a8866ad7f0e17c02b14182d37ea7c3c8b9c2683aeb6b733a1@52.169.14.227:30303,enode://6ce05930c72abc632c58e2e4324f7c7ea478cec0ed4fa2528982cf34483094e9cbc9216e7aa349691242576d552a2a56aaeae426c5303ded677ce455ba1acd9d@13.84.180.240:30303" console
• more; https://ethereum.stackexchange.com/questions/35337/geth-not-syncing-on-testnet

on console, use eth.syncing to see if ethereum still syncs.