To me I believe that bitcoin and blockchain technology can be of help to poor countries with inadequate infrastructures in numerous ways, if been legalize in those countries.
Bitcoin as a decentralized digital currency can allow peer to peer transations without the need of bank in countries with inadequate infrastructure, just with the use of their mobile devices if been ligalize.
Could you believe that blackchain base microfinance platforms can provide access to credit other financial services to small businesses owners and entrepreneurs in poor countries, if been ligalize.
Bitcoin can make transactions faster and easier and also low cost of remittance in poor countries, if been ligalize.
Bitcoin can be accessible and use through mobile devices in countries with inadequate infrastructures, for payment if been ligalize.
Could you also believe that bitcoin related projects can make poor countries develop their internet infrastructures, improving connectivity and access to informations, if been ligalize.
Bitcoin itself is not a magic stick, it can't do nothing if people don't do actual work. I think that the answer to the question
how bitcoin and blockchain can help poor countries lies into the governments of these poor countries. They can use the opportunity and create a business friendly environment for Bitcoin and blockchain related businesses by offering companies low to zero tax rates and a high quality personnel inside the country. I think that countries can spend money on educating their talented citizens about Bitcoin and blockchain technologies and make a very good developer out of them.