Vaani is a free iPhone app developed by Rohit Sethi, falling under the Social & Communication category with a focus on social networking. The app allows users to make both free and affordable calls using the internet. By connecting to a Wi-Fi hotspot, users can avoid international roaming charges and make cheap long-distance calls. Additionally, users can earn free credits by watching ads and sending mobile top-ups.

To get started, users simply need to sign up with their mobile number, password, and email address. Upon successful registration, users receive $0.10 in free credit to test Vaani's services. Once these credits are used up, users can purchase more credits via in-app purchases or earn them by watching ads. Vaani offers a user-friendly interface for making calls, watching ads, purchasing credits, checking calling rates, and viewing call reports.

For optimal voice quality, users are advised to use Wi-Fi for calls and ensure that Vaani has access to its servers without firewall interference. To learn more, users can refer to Vaani's terms of use available at their website.