Exif Tag Viewer is a free Android app developed by M-Apps that enables users to view the EXIF data of their pictures. EXIF tags contain important information such as location, device information, and tools used to enhance the picture. This app is especially useful for those who want to know the details behind their photos. It is easy to use, and it supports receiving and sending intents. 

If you need to modify or add EXIF data, you can check out Exif Editor, which is available on the Play Store.

Exif Editor comes with additional features such as the ability to add, modify, or remove tags individually, modify location data using Google Maps view, copy tags from existing files, batch process multiple images, and batch export EXIF data to text files. Moreover, the app is completely ad-free.

It's worth noting that Exif Editor requires internet and location permissions for the Google Maps view integration. If you have any questions or ideas, you can contact the developer via their website.