Don't let the title fool you: this app isn't a WiFi-exclusive version of Skype. That would be silly. Instead, it's an easy access app for Skype's network of partnered WiFi access points, which the company claims is more than a million strong in various airports, cafes, and train stations. There's nothing stopping you from using them normally (or using the standard Skype VOIP app), but Skype WiFi will quickly connect and authenticate your Android-powered device.
What may be even more useful is the fact that you can pay for access with your Skype credit. While this is obviously less desirable than a free access point, it means that as long as you've got some Skype credit available, you won't have to dig into your wallet for a credit card or go through a PayPal prompt.