If the user just recently signed up and installed an application on their domain but the splash page is still showing up in place of their app, have the user clear their browser cache.
Reason this may happen
The user likely loaded the default page in their browser after the domain was registered and it’s now cached in their browser.
We drop default files (default.html) in every hosting account when the user signs up. These files get overwritten by WordPress, however browsers can sometimes still store the splash page.