Make slim or thin in picture? What is the app people use to make me slimmer in the picture? The app "LittleThinner" makes the object in the picture look slimmer or thinner. As shown in the screenshots, you simply select any photo, then tap the thinner button which keeps the rest of the photo looking normal but makes the object thinner and slimmer as shown. Other features are also included to make wider or thicker, but the main features are to make it appear slimmer. There are also different levels that you can use to make even more thinner if you wish. You just tap save when ready to save your new picture.