http://idcm.io/ will launch RVN/BTC and RVN/ETH pairs live on their exchange and begin supporting RVN on their mobile wallet applications (downloadable at  https://www.idcw.io/) at 3pm Hong Kong time, 18th of May, 2018 (in about 16 hours from this post). IDCM has fully functioning iOS and Android apps that you can use to trade on your phone. They charge a 0.1% trading fee. Any issues/questions/suggestions that you have, hedgedhog is an IDCM rep on our discord channel. Feel free to @ him or DM him.
IDCM is also interested in supporting a USD pair for RVN if there is enough demand. They will make a decision at the end of May, when they will also be lowering the minimum deposit and withdrawal fees for USD to $30 and 0.3%.