Joi 4 g voice is coming in a 4g mobile phone or smart phone.jio voice is very useful for having a Jio at your sis or girl friend house because we can talk with her at no cost from this we can save money for recharging of mobile .Jio 4g voice is very very essential application I s there because if we want to talk with them without a cosy .than we must open the account to have bank account.jio 4 g voice we can talk to other at a free of cost only.so everyone not deleting a application which are running for them