Electrum

Electrum is a super simple bitcoin wallet that protects your cryptocurrencies from backup errors. If your backups get corrupted or your computer has some issue, this application lets you recover your wallet by entering a phrase that only you know.

Electrum offers greater security than other wallets since private keys are never sent to the server, and all information is SPV-verified. Beyond that, Electrum's servers are decentralized, so you can access them at all times, even if some of the servers fail at one point or another.

Electrum supports third-party plug-ins, such as Multisig services, hardware wallets, and more. This application also encrypts your keys and lets you divide permissions between several wallets. To do all this, you'll need to use two-factor authentication via Electrum and Trustedcoin, which provides extra security and prevents possible theft.

Basically, this tool is a great way to keep your cryptocurrencies safe. Download Electrum and set up your own security phrase so you can recover your investments if something goes wrong.