Using the different tools in Facetune is very simple. Should you for some reason have a question, the app displays a short tutorial every time you go to try a new tool. You can whiten teeth, change hair color, stretch skin, and much more.
Once you've finished working on your photos, all you have to do is save it to your phone's memory. That said, to save an image you have to view a video or buy the ad-free version of the app.
Facetune is an excellent photo-editing app with lots of useful tools and an accessible interface. The app is especially designed for retouching selfies but you can make terrific edits to any photo.