I often use my iPhone to scan and send documents. This is how I do it.
There are many scanner apps available. I like Scanner Pro by Readdle the best. It was $3.99 when I wrote this.
Here is the link to the app in the App Store:
Scanner Pro – PDF document scanner app with OCR by Readdle Inc.
After you download the app, open it and click the orange circle with the plus sign.
The app will open up the camera.
The app will autofocus and then take a picture of the document.
You can click on the name (Scan Date Time) and rename the doc. You can also click edit to make any changes or square off the corners.
Then click share and choose how you want to send the document.
If you need to write on the document, you can use PDFExpert.
PDF Expert 6: Read, annotate & edit PDF documents by Readdle Inc.