Add to homescreen

I've been looking for best practices where to put additional link "Add to homescreen". We need to implement it while the user logs in or has just logged in. I do not want to use a pop-up to make it so important for the user as we are not a "rude" website. I was wondering if this is a good practice if I put a small button under the Remember password for those who just wants to open our website a little bit faster.