Simple Scanner Android application

I need an android application or code do be able to use it on my previous applications. It must at least do these features: 1- scan with movable corners to crop the captured paper perfectly and delete any rubbish background. 2- convert the document to grayscale colors. 3- file saved as pdf format. 4- browse button to find the file on scan folder Time to submit = 3 days Cost = $150 Examples for similar apps in google play (cam scanner + mdscan) For the movable corners crop check images below. Only expert freelancer who know how tothe app may bid Many developers failed to do my requirements.