There currently isn't a feature to provide an e-signature for applications. However, there are a few ways to go about certifying submission of applications or providing a signature. The first option is simpler and required less work on the part of the applicant and your organization. Please note that these are simply examples that we have seen from our clients, but you can most certainly choose any method you wish to achieve this goal.
1) You can add a new page titled "Submit Application". In this page, you can create a question with text similar to the following:
"I hereby certify that all information provided is true and correct to the best of my knowledge. I also certify that if I am under the age of 18, my parents/guardians are aware and approve of my application to this program."
Choose question type "Multiple Choice - Multiple Selections" and give only one option, "I agree". Be sure to mark the question as "Required". This will require the applicant to agree to the statement and check the box next to "I agree".
2) You can create a form for the applicant and/or their guardian to sign that they can scan and upload to the application. This will require you to create a form and have your webmaster upload the file to your website.
To require this, you can create a question with a link to the signature form from your website. Simply replace "www.link.com" with the link to the document/file within the code below.
<a href="www.link.com">Download file here</a>
Note that the file must be downloaded, printed, signed by all required parties, scanned, and attached. Choose question type "Attachment". Be sure to mark the question "Required".