Jio4gvoice app is very good and qualified product. There is no need of its usage in all smartphone because every handsets has their own calling apps and clarity of voice and videos. But the thing is that if we want to use jio network in lenovo and chaina phones we need to install jio4gvoice because without this app we cannot use calling or messaging with jio network. So lenovo and chaina handsets in India if you want use jio network you should install jio4gvoice where you will get a best services.