Jose wants to know how to sign a PDF document on his Android tablet and send it back. Leo says that Adobe Acrobat Reader is the best one according to Tech Radar. It will allow one to sign their name digitally and even store the signature to use again. Other options are XOdo PDF Reader. FoxIt. GAAHio. PDF Pen Pro.
Another idea is to sign a name with a sharpie on a white piece of paper and save it as a transparent PNG file. Then he can simply insert it as a graphic.
He can also use DocuSign, which will enable him to legally sign a digital document with verification.