CamScanner is a scanning application that allows you to take high-quality images of important documents. It has automatic image processing features to help ensure that your scans are high quality, and it offers the ability to save them as PDFs of various sizes. It also supports multi-page scans and allows you to search through scanned photos.
Through its integration with Box, you can upload scanned PDFs directly to your Box account.
To use CamScanner with Box, download the application using the "Get Application" button, then install it on your iPhone. Once it is installed, add your Box account and you will be able to upload your scanned images.
On Android you can initiate CamScanner from within Box. Simply click on the OneCloud button, chose "scan" with CamScanner, use CamScanner and automatically save back to Box.