Anybody using digital signatures with ZCRM?

Just wondering if anyone is using digital signatures to sign invoices, quotes etc...

How is it working out? Any issues, pitfalls to look out for?

Do you integrate with a third party accounting software?

I've looked at some apps like echo sign from Adobe... Still a lot of extra clicks to sign. It would be "amazing" if a digital signature field could be added to Zoho!!

Thanks
Kevin