Power Apps now supports creating an app from data stored in lists on a SharePoint 2013 and SharePoint 2016 on-premises site. PowerApps is considered as a successor for custom forms and it is based on open source version of the software called Apache Cordova powered by Resources from Azure app service.

Microsoft is planning to enable embedding PowerApps directly into the SharePoint page so that it can be viewed as part of the SharePoint page.

PowerApps allows you to easily create and share apps from existing data sets, no coding necessary. These data sets include cloud-stored Excel files, SharePoint Lists, and SQL Azure Tables.  

PowerApps has been a great feature. The idea here is that you are able to build forms, specifically for mobile devices and of course the web, that can front your SharePoint data or other line of business applications.

Below are the steps for creating a Power App based on on-premises data

1. Login to Office 365 SharePoint site and Click the list which you want to add PowerAPPs

2. Click the PowerApps Link in the list ribbon like below

3. Click Create an App in Link ,

4. Enter the Power APP Name it will redirect to the PowerApps Studio

   

5. From the Power Apps studio click New from the left navigation bar.

Add Data Source here,

Then Click Connect button to retrive the list items,

Then Select your list and give connect and select Preview link button

Yes .Finally the PowerApps successfuly displayed the list item here.

The form creation process is great and offers a rich experience. PowerApps gives you the ability to connect all kinds of Data that is not only available with you Tenant but connected to it via the Data Management Gateways.

PowerApps truly is the future of building custom forms and then making them available on mobile devices for your organization.