[iMore Question]

Or am I supposed to download something? Because I do not get that option on my phone when I select text.

[Jeroen7]

it is standard functionality, it's not a special feature that you have to download.

I just tried it. the first time i selected a word it only showed a few options, but tried again and then you see a triangle on the right side, hit that and you'll see a B/I option.