The following are apps for fashion or beauty purposes. These are for sure on Android, but are not necessarily for iPhones. These are just some of the apps that I've found. There are plenty out there.
This app is a closet organization app, designed to help you organize your wardrobe, and create outfits from anywhere on your mobile device.
CunPic and DecoPic:
These apps are both created by the same Japanese company. CunPic allows you to beautify your photos, while DecoPic allows you to put cute stickers on the photo. Both of the apps are compatible with one another, meaning that you can edit a photo on CunPic and then move it into DecoPic directly to start decorating it. They also post straight to several social networking sites.
This app contains remedies for common beauty problems such as dark spots, dry skin, etc. (Recipes included.)
(The app looks like a woman at the spa. Couldn't get a photo.)
This app is for the Gothic Beauty Magazine, and contains several articles, several of which are fashion related.
YouCam Makeup-Makeover Studio:
This app is designed to allow you to change your hair and makeup in a photo to try out new styles and colors.