Hi there,
I can create this tool for you. Would be cheaper if you would provide the text pasted into a field, so if you're fine with such a solution where you'd paste the whole text into a field I can drop the price for 60€.
If you need doc, docx and pdf support then the price remains as in my bid.
I would make it so it checks line by line on google, and if there are results with an exact match then it would count that line as plagiarism, otherwise as original. At the end it would give the result with percentage of plagiarism and the sources of the plagiate lines.
Regards,
Julijan