Jio speed is quit good but the call feature not very good.so, jio launched a software jio 4G voice for better call experience.
as we know "if we try to call from jio sim the call always disconnect and call drop problems occur" so, jio launched this app for solve the problem but it can’t work as we except. I suggest you to don’t use this app it can’t work but also hangs your phone for few minutes please don’t use this app. carry a sim of another operator for calling.
Thanks