JST is a part of the USDJ currency system. Holding JST can participate in the community governance of JUST and pay the stabilization fee for CDP borrowing in the JUST system.
Crypterium (CRPT) is a popular token available on major exchanges and through Crypterium app. It is the principal token of the Crypterium platform. You can buy these tokens with fiat (hard) currency, BTC, ETH and a number of other methods.
In 2019 summer, CRPT swapped to the Binance Chain.