Thank you for your post.
At this time, FileMaker Go cannot detect if an application exists on an iOS device. I recommend that you enter this as a product suggestion into our Feature Requests web form at:
The entries into this web form populate a database hosted by our Development and Product Management teams, where each entry is discussed and considered for a future release. Although I could copy your post and paste it into the web form, there are a couple of questions asked that only you can answer.