It will save alot of paper. Thanks to Zoho Book we now send most of the invoices thorugh email, its quick and easy and Eco Friendly. However, some clients place multple order and require challan along with the invoice, for which we need to handle it manually using conventional methods (hand made delivey challan). If we can take their signature direclty on the delivery challan in mobile, it will make the work very eco friendly and again time saving.