I did a Space Invader hunt in Paris about 7 year ago and used Invader's map (an early paper version). It was still fun! It was nice to have an idea which neighborhood to go to then take my time and look. It wouldn't be fun if it were too specific though, like an AR app guiding you to the exact spot.

The most fun for me is seeing them as a surprise. Most recent example was in Bilbão, a beautiful site on the river near the gorgeous old train station. Enjoying all the scenery and then bam, there's an Invader, placed just perfectly to be visible but unobtrusive.