StashPixFree automatically recognizes faces on the screen and adds a mustache to them, even as the camera is moving. Such a concept could make for a fun app, but unfortunately StashPixFree never builds on this basic idea and the result is ultimately forgettable.
The app does nothing else, the interface is very limited, and the ads are intrusive, but the delivery of the primary draw in this app is well done. It effectively displays and tags each image with a classic curlicue mustache as you take the photos. Of course, being a one-trick app has its limitations. You cannot edit images after taking them, sharing options are limited to those built-in to the app, and the interface goes directly to the camera. There are not even any settings to change or adjust the type, size, or color of the mustache. In total it creates a funny trick that will likely be used once or twice and then left alone.
StashPixFree is a free app that works as advertised but doesn't go above and beyond initial expectations in any way. As a result, it is a fairly limited app that will be funny for a few minutes, but ultimately never do much more. If you'd like to see a mustache added to your friends' faces in camera, give it a go, but for long term photo editing or joke images, this is not the best app on the App Store.