imageshow can already be used in uifigures and apps. imageshow must be parented to a Viewer object and the Viewer object can be parented to a figure (including uifigure), Panel, GridLayout, or Tab object.
Example: viewer parented to uifigure
uif = uifigure();
viewer = viewer2d(Parent=uif); % or viewer3d
I = imread("pout.tif");
im = imageshow(I,Parent=viewer);
R2024b
Example: viewer parented to uipanel
uif = uifigure();
uip = uipanel(uif);
viewer = viewer2d(Parent=uip);
I = imread("pout.tif");
im = imageshow(I,Parent=viewer);
