Migrant workers often send at least half of their pay to their families in their home countries. In the process, they have to pay for transfer fees and currency exchange rates which may run above 10 percent of the transaction amount. Everex is a startup aimed at solving that problem. Everex is based on the blockchain, the technology that records a secure digital ledger of transactions of cryptocurrencies like Bitcoin. Using a mobile app for cross-border transfers isn’t a new idea, but blockchain technology makes it more secure. The company offers a full refund if a transaction doesn’t work.