Actually I am a airtel user so I also uses my airtel app. It offers very much but the performance is not very good. It is just like, quantity is more but the quality is less as it never gives me right information about my data usage so I always confused in measuring the remaining data and this shows the weak performance.
And a more rough thing about this app is its interface due which I face a lot of problems in chosing the right among all given there. And it also uses the phones storage as its storage increases with time.
Actually, airtel uses this app for promoting its another apps as airtel tv or some other of its own.