Hi, there should already be a GestureDetector that invokes dismiss() when tapped:

matthew-carroll/flutter_ui_challenge_feature_discovery

For your timer situation, you should be able to use WidgetsBinding.instance.addPostFrameCallback(…) instead. Here is a PR that Simon Lightfoot submitted to solve this problem in the Fluttery library:

Bug fix for modifying overlays during build. by slightfoot · Pull Request #2 ·…