I'd like to put in a word here for an app I wish I hadn't needed—although I expect it to be useful in the future, too.
In Basel, Switzerland, on a Sunday and needing to submit documents to travel insurance, I had no access to a fax or a scanner. Only my Android phone. A quick search turned up Adobe Scan, a free app that uses your phone camera to turn documents into PDFs, and can even recognize text and turn them into Word documents.
Essentially, you open the app, hold your phone above the document so that all of it appears in the camera window and wait while the app focuses and takes the picture. It then appears on the screen in a blue frame that you can expand, contract, reshape or shift until it correctly surrounds the image you want. The app then 'straightens' the image so it appears as it would if scanned,
Saved my forms and images to my phone that way, and then emailed them in.