I am a huge fan of this app personally guys.
This is the app which I use to click any pictures of the documents like aadhar or driving licence or mark sheets or bank passbook and convert them into Pdf which gives the same feeling as if it was actually scanned.
Like if you want the back and front of a document in a single scanned copy, never fear CamScanner is your deal. In CamScanner you can combine multiple number of pictures into a single pdf.
For example I was asked my bank account statement for opening a demat account, so I clicked multiple pictures of my bank passbook which included front page and last 3 months statements then I combined them into a single Pdf by even renaming the pdf file.
CamScanner have always come in handy for me. It is the best in the market.