Thank you for your post.
At this time, FileMaker Go does not have the ability to default to a specific database file on launch. The Getting Started file is used on initial launch.
I recommend submitting this suggestion to our Feature Requests web form at:
The entries into this web form are populated in a database file that is hosted by Development and Product Management, where the suggestions are discussed and considered for future releases. Although I could copy your post and paste it into the web form, there are a couple questions asked that only you can answer.