Plants vs. Zombies has long been among the most popular games on both Android and iOS, but it's always come with a price tag. That's suddenly changed, however, now that PopCap has made its garden slasher app available for free. Previously priced at $2.99 on iTunes and Google Play, the iPad-compatible HD app is only free for iOS users, and it remains unclear whether PopCap will offer a similar discount for Android gamers. It's also unclear how long the offer will last, but if you have yet to try your hand at mowing down cartoon zombies, now would be a good time to start. You can download the app here.