JustVoip is a free Android app developed by Finarea that offers extremely low rates for making international calls. It allows you to use your smartphone to take advantage of cheap rates anywhere, anytime, making it an excellent choice for calling family and friends overseas. The app keeps its prices consistently low while maintaining high-quality service.

Although the app provides superior quality and cheap rates, it's essential to note that using JustVoip as a default dialer may interfere with dialing 911 emergency services. Therefore, it's crucial to be cautious when using the app. Overall, JustVoip is an excellent app for anyone looking to make international calls without breaking the bank.