Works around NAT, filtered and fire-walled networks! PTTJapanPlus is a free android calling app which lets you make cheap national or international voip calls directly from your Android based phones even behind firewalls. You can save on your Mobile Phone costs by simply installing thePTTJapanPlus app and start making cheap calls.PTTJapanPlus offers free 3G calls or WiFi calls for Android, and iPhone and PC users! Save on monthly calling charges!- SMS and Chat- Place FREE voice On-Net calls to other PTT buddies.- Enjoy the cheapest international calls to any other destination.- Cheaper than Skype!- Cheap MobileVoip callsSimply install our free calling app, sign up and start calling in a minute with the lowest voip provider on the planet earth.