Nerva is described as 'NERVA (XNV) is an untraceable and secure cryptocurrency aim to be GPU and ASIC resistant via the new Cryptonight Adaptive POW algorithm. NERVA offers true privacy and fungibility, is untraceable and unlinkable, with users and transfer amounts hidden' and is a cryptocurrency coin in the bitcoin & cryptocurrency category. There are more than 50 alternatives to Nerva for a variety of platforms, including Mac, Windows, Linux, Online / Web-based and Android. The best alternative is Bitcoin, which is both free and Open Source. Other great apps like Nerva are Monero, Ethereum, Litecoin and Flattr.
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.
Flattr is a social micropayment service, that makes it easy for you to "flatter" things on the internet that you like. When you're registered to Flattr, you pay a small monthly fee of your own choosing.