If I change my theme will the app still work?

Stencil based themes

There should be no issues in changing themes, the app code will transition to the new theme. Some newer themes have started making a large part of the product page not visible when out of stock. This can interfere our form displaying.

If the form is not displaying after a theme change or upgrade see the solution article:

I just switched to a new theme, how do I get the app form to display again?

Blueprint themes (older)

When changing themes in the older blueprint system, this removes the code on the footer.html file that connects the app to the theme. See the solution article I just switched to a new theme, how do I get the app form to display again?