Samsung will almost certainly launch a Samsung Galaxy S9 Plus alongside the standard Samsung Galaxy S9, if past form is anything to go by.
And based on previous launches we can predict that this will be a bigger phone than the S9, with a larger battery too, but otherwise very similar.
The information disseminating onto the web about the Samsung Galaxy S9 Plus has yet to reach groundswell, but there are a number of Galaxy S9 rumors which we can use as a starting point.