You need a computer with an USB port, and a recent version of Google Chrome. The ledger hardware bitcoin wallet can also be hooked up with other wallets like mycelium and coinkite.
It works on Windows, Mac and Linux.
The wallet interfaces with the computer through a Chrome application which you will need to install on your computer.
No additional software installation or account creation is needed.
The Ledger Wallet is self-sufficient and allows several coins to be used like BTC, ETH, LTC, DOGE, ZEC, STRAT and XRP