Looking to incorporate a file viewer and E-signature feature.

[hukaslart]

Hello! 

I am looking at Re-creating my ski team website. The two major things I will need to do so is file viewing and E-signature capabilities. Just wondering if anyone knows of a theme that maybe already has this incorporated/an app that accomplishes this or if there is any other way I could get this done within shopify? 

Thank you in advance!