As stated in the WordPress Codex, by default WordPress shows your most recent posts in reverse chronological order on the front page of your site. If you want a static front page or splash page as the front page instead, you may select it using the "Front page display" setting Dashboard » Settings » Reading.

Some themes, however, ignore this setting and define their own "front pages". These pages cannot be accessed or A/B tested by Nelio. However, if you want to be able to track Heatmaps for such a front page, simply select "Theme-based Front Page" in Nelio's Miscellaneous Settings and you will be able to select that front page during the creation of a Heatmap Experiment.