Invitation Code Error
The most common error on Installr is the "Cannot find invitation code" error, pictured below.
It's most commonly caused by not being in standalone Safari. For example, if you tap the link from the Gmail app, you'll still be inside Gmail. You'll need to tap the Safari button at the bottom-right, as pictured.
If you're opening the link in full Safari, the next most common cause for error is opening in private mode. Just for this download, you'll need to be using Safari in regular browsing mode.
To turn off private browsing, tap the window button at the bottom-right, then the private browsing button at bottom-left, as pictured below (picture is showing Safari in private mode).
If you're still having installation problems after following these steps, just email me at firstname.lastname@example.org.
I aim to respond back in less than 10 minutes.