Your client may not like this solution. However, I have found the best way to handle it, to look (dimensionally) correct on all devices, is to use letterbox. Then extending the background by filling the black bars in. Usually with rects matching my background color. This can be done on the fly at startup. For a more complex background you can use additional images that match the design.
In the long run letterbox will also probably save you grief if the buttons are burnt into the background. Calculating where the buttons may end up if they get stretched would seem like an impossibility. With letterbox, everything is the same code wise, Corona handles the scaling. A button will always be in the same x/y range.
Not knowing what the background actually is for your client’s app, it may not be as easy as creating a color filled rect. However even having images to extend it could be less work/time/money than creating the entire background over and over for several different device sizes.
No matter what you do, if your dealing with Android your going to run into sizes that don’t fit your background size. There is no standard across the board for Android. Motorola likes making phones with extended heights. Tablets range all over the place.
In the end, show the client what zoomstretch would look like on a device or two. If they are ok with it, theres your answer. Some people don’t notice things, others are very observant. I can only speak for myself. Even if I can’t say why something like this looks odd, I would probably think, something is not right.
Hopefully my 2 cents plus an addition 2 cents are useful. 
[import]uid: 56820 topic_id: 24444 reply_id: 99078[/import]
