BlackCoin is described as 'Blackcoin is a scrypt based coin launched on February 24th. It boasts 10 second transaction times (very fast), and unlike most other coins, can't be mined anymore' and is an app in the Bitcoin & Cryptocurrency category. There are more than 50 alternatives to BlackCoin for a variety of platforms, including Online / Web-based, Windows, Linux, Mac and Android. The best alternative is Bitcoin, which is both free and Open Source. Other great apps like BlackCoin are PayPal (Paid), Monero (Free, Open Source), Ethereum (Free, Open Source) and Litecoin (Free, Open Source).
Bitcoin is a peer-to-peer digital currency. Peer-to-peer (P2P) means that there is no central authority to issue new money or keep track of transactions. Instead, these tasks are managed collectively by the nodes of the network.
Monero is a digital currency that is secure, private, and untraceable. It is open-source and freely available to all. With Monero, you are your own bank. Only you control and are responsible for your funds, and your accounts and transactions are kept private from prying eyes.