is there any way to add an icon for an app which is also available in lightning. In Classic I have uploaded an image in document object but in lightning we don't have a document object thats why icon is not coming when we select an app in lightning. Is there any work around ? Any help will be appreciated.
Switch to the "Lightning Experience" UI and go to "Setup Home" in that. Then in Apps -> App Manager you can create a "New Lightning App" or edit a "Lightning" App Type existing App definition and upload an image as the "App Branding" image.
(For an app that works in both Classic and Lightning use a separate App definition for each case.)
If you want to extract that image back out into version control see How to extract the application brand logo image over an API?.
The Lightning App image is stored in a different way to the Classic App image so the same image cannot be used; a different size and shape is typically best in any case:
- Classic: The image must be in GIF or JPEG format and less than 20 KB in size. If the image is larger than 300 pixels wide by 55 pixels high, then it will be scaled to fit. For the best on-screen display, we recommend you use an image with a transparent background.
- Lightning: App images represent your app in Lightning Experience and Salesforce1. Choose a JPG, PNG, BMP, or GIF image that's smaller than 5 MB. For best results, upload an image that's 128 by 128 pixels. Images larger than the maximum display are resized.