Viewport on Samsung tab & iPad

I’m working on an app now for ipads and tablet size screens.
Samsung tablet is 1256h x 800w
iPad 1673h x 1280w

To make my life easier to make the app run on both devices, is it possible somewhere in meta tags to scale the viewport?

I played with this

<meta name='viewport' content='width=device-width, initial-scale=1, user-scalable=no viewport-fit=contain' />

initial-scale only zoomed the page, taking part of the intended window off screen.
Is there a balance of width and scale I need?

Any tips, greatly appreciated.

I have found a solution which seems to be ok.

    sc = window.innerWidth / 800
    $("head").append("<meta name='viewport' content='width=800, initial-scale=" & sc & "'>")
    NSB.MsgBox(window.innerWidth & "px wide","OK","iPad")
  ScrHeight = document.documentElement.clientHeight
  ScrWidth = document.documentElement.clientWidth

Any window.innerWidth calls I had in my app I replaced with the variable ScrWidth but ...clientWidth would work ok.

I know there is responsive design there but for the apps I design I can’t get the look that I think is needed for what they do, or I may just be an old dog.