App designers can change the form screen icons shown within the app from the default set to either a different set available on the platform or icons of their own design. All icons must be in portable network graphics (PNG) format and no larger than 50 kilobytes (kb) in file size and 192x192 pixels in dimension.
Changes can be made by navigating to Apps > Apps Setup:
On the App Setup page, click "customize icons" beneath the page title:
Here the entire set of Screen Icons will be visible in the main content area of the page, all checkmarked by default. Unchecking any icon and clicking the "Save" icon in the upper-right corner of the page will remove its availability for use within the app. If any app is using an icon that is removed, the app will have no icon until another one is selected within the app's Settings page, or until the icon is restored by rechecking its tickbox here and clicking "Save" again.
Above the Screen Icons within Icon Set & Stying, the Icon Set is set automatically to Default but can be changed to several other provided icon sets. To make a different selection from these options, choose an option from the drop-down menu and click "Save" in the upper-right corner of the page. All icons in the app will be adjusted accordingly.
To change an individual icon rather than the entire set, click the "CHANGE" button beneath the icon and select a replacement file from the file explorer window. Then click the "Save" button in the upper-right corner of the page to apply the change. Remember that all icons must be .png format and no larger than 50kb.