As a freelancer, I needed to make contracts with the clients I worked with. I found PandaDoc, where I can create templates of documents and share them with my clients, who signed them digitally.
PandaDoc lets you add elements like signatures, dates, initials, etc to your agreements so clients can sign them without having to install a third-party app. Once signed and completed by the client, the digital copy of the agreement also provides a "Signature Certificate" with the name, date, time, and other details about the document, thereby increasing its authenticity.
The free version of the app is very useful, but the subscription plan is beneficial for businesses that want to keep track of their clients and increase productivity.