I've spent ages trying to solve this problem before eventually throwing in the towel and deciding to saddle this forum with it.
An FM solution starts up fine in FMGo, adjusting the window size to fit the screen of the device it is running on. This is effected by a script triggered using "OnFirstWindowOpen" which contains the Adjust Window step with option "Resize to fit". The background image, which resides in the body, is proportionally correct and autosizing is set to include left/right/up and down. There is no footer.
However, when deploying as a FIAS App and testing on the same iPhone, the window always opens with the bottom edge slightly off screen and I have to pinch zoom to get it to fit, after which the layout is spot on for the rest of the session. I have triple checked the layout settings and these are all correct for all objects on the layout. I have also tried triggering the script using "OnWindowOpen", as I read that startup scripts may not always run when expected within an SDK build (I guess when the App is running in the background and brought to front), but without improvement. No toolbars are on and I've tried "Maximize" and Zoom level of 100%, all to no avail. I've looked in Xcode, but can't see anything obvious.
Again, it works perfectly in Go and is identical in FIAS down to the last pixel after pinching.
A small problem, but an annoying one.