At Google I/O 2018, it was announced that Chrome on Android will no longer include an automated add to homescreen prompt. Instead, it is your responsibility to create the user experience. Ultimately, the Chrome team decided to fall more in line with how other browser vendors are crafting their experiences.
The manifest specification takes time to define skeleton rules and minimal requirements for the add to homescreen experience. Rather than limiting all browsers to the same rules, the specification defines instalability signals that can be used as part of the add to homescreen prompt algorithm.
The prompt sequence should honor a modicum of privacy considerations and wait for the document to be fully loaded before issuing a prompt. The process should also allow the user to inspect the application name, icon, start URL, origin, and other...
