Aeon is a mobile-friendly, lightweight privacy coin. Similar to the way that Litecoin is a lighter supplement to Bitcoin, you can look at Aeon as Monero’s little brother. The Monero community is wholly focused on privacy and anonymity for the end-user. This focus has its perks but has caused the coin to fall behind from a usability standpoint. Aeon builds upon Monero’s CryptoNote hash while adding some lightweight functionality of its own. Aeon is the lighter, faster version of Monero. Although both projects share the same underlying privacy protocol, CryptoNote, Aeon is striving to be more accessible. The project is doing so by implementing a lightweight mining algorithm, smaller blockchain, and optional anonymity. As Monero grows, Aeon could very well grow with it. While you would use Monero for transactions in which you want to assure privacy, you may find Aeon to be a suitable substitute for day-to-day exchanges in which guaranteed anonymity isn’t as important.
Mastercoin / Omni is a digital currency built on top of the Bitcoin blockchain. Its features include the development of a decentralised exchange and the implementation of smart property and savings wallet. The Master Protocol facilitates the creation and trading of smart properties and user currencies as well as other types of smart contracts. Mastercoin enables the Bitcoin eco-system to become more decentralized. The Mastercoin project was launched on 31 July 2013 with a one-month long fundraiser. Those interested in obtaining Mastercoin may send bitcoin to an 'Exodus Address' where the funds collected would be used to fund the development of Mastercoin. Around 500 people invested in Mastercoin sending roughly 5000 bitcoins to the Mastercoin project.