The developers of EXIF Viewer are having a promo photo app sale, offering their app for free when it’s usually US$2.99. The app lets you view and edit photo metadata, which is useful for changing GPS data, time and date stamps, and more. It also lets you remove metadata, which is useful to sharing photos to social media. This prevents people from viewing the metadata to see where you took the picture. It works through the share sheet so you don’t even have to leave the Photos app.