A free program for Android, by Tresor Tech.

Document Scanner – PDF Scan is an application that will let you scan any document or photo into a PDF file. This app has the capability to do a lot of things, such as taking a photo and making it into a PDF file, and also converting a document from PDF to JPG or JPEG. It is very easy to use, you just have to select the file that you want to scan, choose the mode you want to use (photo or document), choose the paper size, and then you can just tap the scan button and the app will do everything for you.

This is an application that is very easy to use, so if you have never used this app before, you will not have any problems using it.