Schwartz finds one glitch with the Xumm app feature but says it is “really nice” still. Ripple chief technology officer David Schwartz took to Twitter yesterday to promote Xumm wallet’s decentralized exchange (DEX) Trade app feature. It bears mentioning that the Ripple executive has been in the United Arab Emirates for at least a week The post Ripple CTO Promotes Xumm Wallet DEX Trade Feature in Dubai first appeared on The Crypto Basic .