Venticake, the creators of Retrica, has developed the application for Android an Apple devices but, sorry, there’s no Retrica for Blackberry specific version. The good news is that if your system version is greater or 10.2 then you can import Android applications using APK files. If it’s your situation: Go to Play Store, download the Retrica APK (and install it on your mobile phone.
If your are the owner of an older version of BlackBerry system, you should search for other options. One of the most famous application, on Blackberry world, that will help you to forget about Retrica is PicMix. On PicMix you will find a great number of filters and frames that will help you to improve your photos.