Since it launched in March, the iPhone version of Sparrow has received a multitude of updates — including the recent addition of POP support — which have helped make an already strong email client even better. But if you've yet to grab yourself a copy, starting today Sparrow is on sale for a limited time. For the next two days the app's available for $0.99, while on Thursday the price will be bumped up to $1.99. Friday will see Sparrow on iPhone go back to its regular price tag of $2.99. If you're unsure whether or not it's the app for you, be sure to check out our full review — and if you end up loving it there's great news, as an iPad version is already being teased.