How to install Filter Packs
Filter packs give Squash new abilities that you can apply to your photos.
Once you'd be purchased a Filter Pack, you need to download the .squashEffectPack file to your Mac. The download link will be in the purchase confirmation email.
Once downloaded, double click the effect pack in the Finder to install it into your copy of Squash.
Your newly installed filters will appear in the Squash sidebar.
Make sure you've previously run Squash on your Mac before attempting to install Filter Packs. Running Squash at least once will let your Mac know that .squashEffectPack files are associated with Squash.