Walmart has a number of other low cost smartphones available, which will compete against the Nokia Lumia 521. For example, the HTC One V, which has slightly lower hardware specifications (3.7 inch WVGA screen, 1GHz single core processor, 512MB RAM, 4GB internal storage, and running Android 4.0), is available pre-paid on Virgin Mobile at the same price point. Another handset at the same price point is the LG Optimus Q (3.2 inch WVGA screen, 1GHz single core processor, 512MB RAM, 3GB internal storage, and running Android 3.2). Both these Android handsets offer good value for money, but it's probably fair to say the the Lumia 521 will offer a superior software experience, because, in general, Windows Phone offers better performance (speed, usability, battery life) than Android when running on similar specified hardware, especially at the low end of the smartphone market.
There are also a number of cheaper Android handsets that undercut the price of the Nokia Lumia 521, such as the Huawei Ascend II ($49.99) and the T-Mobile Prism ($99.99), though these are notably inferior in terms of both specifications and software experience. However, this does means that Android powered devices retain the cheapest smartphone crown by some distance.
Via: WMPowerUser