GreenAddress is a solution created by Lawrence Nahum, the CEO, and creator of the wallet, alongside with Jerzy Kozera, a full stack developer. Although only these two people are in charge of development, GreenAddress was one of the first bitcoin wallets to deliver features like HD multisig, hardware wallet support, dynamic fees, and transaction replacement.
Perhaps one of the innovative features provided by this wallet is the one named “nLockTime”, to better explain what this feature does, you first need to understand that GreenAddress works with a multi-signature bitcoin address scheme. When you create an account, you receive only a portion of the private key, and GreenAdress stores the other half. In essence, you need the company’s approval to sign your transactions, or else they won’t be broadcasted to the bitcoin network. This allows GreenAdress to offer instant transactions to its clients (zero-confirmation TXs).
Having a 2 of 2 signature address is something that most hardcore bitcoin enthusiast may reject at first glance, however, the nLockTime feature allows you to redeem your deposited funds without GreenAddress’ signature after a pre-defined number of blocks. You can also create ‘simple accounts’, allowing you to access your funds at any time even without access to GreenAddress, using additional offline recovery keys.
The wallet uses a 24-words recovery passphrase, a figure typically found in hardware wallets (in comparison, the Electrum wallet uses a 14-word recovery method). The fees set by default on the app are also a common source of complaints. However, the wallet does offer you the possibility of manually entering the fee.
The main issue with this wallet provider is the stability of the site. Users claim hardship loggin in to their wallets which is what keeping this company from dominating the bitcoin wallet market.
On July 27, 2016, the startup disclosed a partnership/acquisition by Blockstream –a venture focused on developing Bitcoin-oriented solutions–. Lawrence Nahum stated that GreenAdress was set to deliver “a multi-platform wallet library to enable more rapid development of all platforms, enhanced privacy and security, and of course sidechain support”.