You can rotate the text as long as you have just the text only, because if you already have your picture and then you add the text on top you will then rotate the whole picture.

So have a canvas with just your text on it, then click on Animation – Rotate – then set the direction either left or right and check the 90 degrees box and click ok.
If your not happy just undo it by clicking Edit – Undo and then you can do it again.
Then if you wanted to add this rotated text on top of another picture just have your other picture opened as well, then on to the text canvas just click Edit – Copy, then on your picture canvas click Edit – Paste into selected frame and then hover over your picture and then left click to place the text onto your picture.

Hope this helps =)