Fether wallet runs Parity Ethereum light client in the background if no other node is found running on the machine. Fether allows reaching the top of the blockchain in a matter of minutes. the Parity team says it is still working hard to bring syncing down to a few seconds, which can be achieved in tandem with further light client updates to Parity Ethereum.

For testnet only

Because the code has yet to be audited, Parity advises not to use Parity Fether on the Ethereum mainnet or use it for anything other than test usage. Upcoming releases of Fether will focus on stability and user experience improvements, including adding BIP39 seed phrase support and Parity Signer integration.

Built using Light.js, a light-client library for DApps

To lower the barrier to entry to developing with light clients, Parity developed a high-level reactive javascript library called Light.js, specifically created to easily develop front-end applications that interface with a light client. It abstracts specific aspects of the development to let developers concentrate on their application’s logic. While building applications relying on a light client is very similar those relying on a full node, light.js helps Dapp builders use the best development patterns.