http://www.coindesk.com/rushwallet-delivers-fast-frictionless-login-free-bitcoin-wallets/

My concerns ----> "Created in 2011, Instawallet had over 1 million accounts and was once lauded by bitcoin developers for its ability to quickly create and use bitcoin addresses. But, a 2013 hack saw it fraudulently relieved of all user funds.
 
Hackers were able to gain access to users’ secret URLs, which were stored online. Instawallet later replaced most users’ balances after a 90-day claims process."