in my experience the layouts do not look the same on iPad vs the computer or even from windows to Mac.
I have been designing a solution to be used on iPad, Macs and Windows and have found that I needed to customize layouts for each platform, then use a platform checking script to direct it to the correct version of that layout. There is some work in customizing the layouts, but for the other two versions you just have minor tweaks to field positions and some fonts.
As Mark pointed out The size of the screen between PC/Mac and IPAD is different. So, to keep things fit to screen, if there are two many controls on the screen then you might split it to tab for the purpose of Ipad/Iphone, Generally, you need to have two/three layouts of the same screen (say Customer_entry_IPAD, Customer_entry_PC, Customer_entry_IPHONE). Using the platform check script/function, you can direct the user to corresponding layout. But this will work fine for small to medium sized apps. But for others, you may have to have seperate fp7 files.
To know more about this by yourself, I would suggest, please investigate the download of free template from this link. It may be too much for a beginner, but still it will give good idea of the approach. Have look at the screenshots of Desktop/Ipad/Iphone.
If you use IWP you will discover browser issues where some things must be adjusted for the individual browser but Filemaker does not provide the tools to tell you what browser is being used. Also, various designs will not work in IWP.
The best method is not to throw a finished layout at IOS or IWP but to build and test unique layouts for each platform and test as you go. A layout for Macs, PCs, iPhones, iPads, IWP (yikes) is not unusual and is prefered. One layout can work cross-all but not as well as one specifically designed for the platform and device.
Filemaker does not update its software often enough to keep up with changes in browsers, html or css so IWP can be a challenge.
Thanx to all, for the replies. The work of making custom layouts for different platforms is not unknown to me, it is something that I was used to do web developing SQL/c# desktop apps with a "child" webapp. It was important to find my primary route at this point since I was not aware of the web features on FMPro engine. So I will keep my first goal to do a desktop Mac friendly layouts, then as needed, design the layout to the requiered platforms. Thanx all