More options for the programmable keyboard key?

[rattyrayvn]

On my old Galaxy Trend, I could set the programmable key (left of the space bar) on the default Samsung keyboard to one of eight choices, including an apostrophe which I found really useful. I just got a new S6 and the only punctuation options for that button are , ? or !

Is there any way to get more options? I tried downloading Google Keyboard but it just has a comma button there.

(Reposted from a guest Q&A post!)