smartphone app for free calls w/number

Does anyone know if there are apps for windows phone 8.1 or android (wm8.1 is better for me)that provides free calls and also provides you with a number that can be used in Japan.

Skype is the only one I know that provides a number so I can use in japan, but they have a monthly charge, is there any others.

Have you tried "Line" app? I used it while I was in Japan...but if you're calling multiple places in Japan, then you might want to rent a sim card or phone....

I've used line, not very good, and you need the other party in your list to make voice call.

Is there something like Skype which provide you with a Skype number.

thanks.

Services that offer a free number are few and far between. I've used several over the years, but they either ended up stopping service after a while, or had terrible call quality. The best free (and still active) service that I've used so far is google voice, but you have to be on a US ip address to sign up. Otherwise, expect to pay a small fee for most voip numbers, either for the number itself or for calling credit.

BTW, do you need a Japanese number specifically, or just a number that people can call you on when in Japan?