LLCrop allows you to either remove unwanted outer areas from a jpg-photo or to create zoom-ins. Simply load a JPEG image from the in-app image browser, adjust the rectangular selection, rotate it if necessary and save it as a new image file. While there are many apps capable of cropping images (often with additional features), they generally cause quality loss because they re-encode to JPEG again when saving the output file. LLCrop (the "LL" stands for lossless) can crop JPEG images without quality loss because it crops the raw JPEG image without re-encoding the file. It also preserves embedded metadata (EXIF/IPTC and XMP).