One of my big gripes with BlackBerry 10 is that you can't (yet) set a separate lockscreen and homescreen wallpaper. You get to choose one and it shows for both, which isn't the best solution. I'd love to be able to pick one wallpaper for my homescreen and a totally different one for my lockscreen. Enter Lockscreen Wallpaper. The new app from Bellshare lets you specify a separate wallpaper for your lockscreen to give you that extra bit of customization.
The one catch here is that due to the limitations of the current API's, you have to keep the app running in the background as an Active Frame. It's not the developers fault so don't blame them. Once you can get by that however, it is a great app if you're looking to change things up a bit. You can choose any image on your device to use for your lockscreen and even have it change at random. It's only $0.99 and when the new API's come out and make the app even better, you'll be able to upgrade for free.