Particl (PART) privacy coin fuels the Particl ecosystem. You can buy the coin on the number of custodial and non-custodial exchanges alike. The fiat purchase with EUR is supported by the Litebit exchange.
Horizen (ZEN) is the native cryptocurrency of Horizen blockchain. It can be mined. Much alike Zcash, ZEN offers regular and shielded addresses. A number of exchanges feature ZEN, including USD as a pairing choice on Bittrex.
Po.et (POE) is the Ethereum token used by the Po.et network to incentivize content creation. This digital asset is paired against other cryptos (such as BTC and ETH) on a few exchanges.