Any tool for esignature that can take my customers sign in real-time?

www.SkySignature.com lets you sign contracts in real time and its free!

To have your customer sign the documents in real-time, you should ideally be carrying iPad or any tablet kind of device. Carrying devices can make it easy for you to have your customers signature on the go. You can look for Hellosigns business plan. Its business plan offers in-person signing feature, using which you can have people sign documents in-person on your iPad or Android tablet. 
DocuSign also provides this feature in its Business Pro plan.
Both the plans by Hellosign and DocuSign cost the same ($40/month) at this moment.