Many business transactions require a signature on an iPhone or iPad device.  By providing a mobile app for digital signature capture, companies can help their users reduce the amount of documents they need to carry around with them and ease storage and retrieval of signed materials.

Developers has the option to either develop this feature from scratch or use an existing commercial library/component like SignatureXtra. SignatureXtra is mentioned here as it has one distinct feature – the signature can be saved in a compressed string for storage in a database.