Installing Virto SharePoint Forms for Office 365
1) Download the Forms Pro from the product page Link.
2) Add it in the app catalog on your site in "Apps for SharePoint".
You will find the app catalog library by navigating to your Office 365 admin center, selecting "SharePoint" under the "Admin" section, then the "apps" navigation link left and then App Catalog under the listed links.
Depending on your O365 subscription plan you will need to navigate to your app catalog directly using the web address: https:// [your_domain_name].sharepoint.com/sites/AppCatalog/.
3) Go to the site where you will add Forms Pro for Office 365:
4) Click “Site content”, add a new app and choose the link "From Your Organization", click "Forms Pro for Office 365 by Virto" icon and trust it.
5) After that Virto Forms icon will be added on the Ribbon pane, so you can launch it directly from your Lists or Document Libraries. Or you can launch it from Site Contents on Site Collection where you've installed Forms Pro App.
6) Now you are ready to create beautiful custom forms in your SharePoint!
The installation is completed.