IOTA is described as 'Open-source distributed cryptocurrency focused on providing secure communications and payments between machines on the Internet of Things. Using directed acyclic graph (DAG) technology instead of the traditional blockchain, IOTA's transactions are free regardless' and is a cryptocurrency coin in the bitcoin & cryptocurrency category. There are more than 50 alternatives to IOTA, not only websites but also apps for a variety of platforms, including Linux, Mac, Windows and Android apps. The best IOTA alternative is Bitcoin, which is both free and Open Source. Other great sites and apps similar to IOTA are Monero, Ethereum, Litecoin and NameCoin.