A lot of schools have their copiers set up to scan documents, which can be delivered in your email in a multitude of formats. The format usually is a black & white PDF, but what if you want color? Or have some photographs to scan? That’s where an app like Camscanner (iOS & Android) comes in handy (there are other scanner apps, so if Camscanner doesn’t float your boat, try another). Scanning apps allow you to quickly capture photos or papers.
“Why don’t I just take a picture?” you may ask. A picture is ok, but the beauty of using a scanning app is the ability to correct for skew and get an image that is square (as in the sense the corners are 90º, not that the resultant scan is square). After you take the picture, you can adjust the image and the software will adjust the skew of the final scan.
The other nice feature of using a scanning app is the ability to combine multiple scans into one PDF. I’ve used it to archive handouts from conferences, so I didn’t have to carry papers around the rest of the time.