Center the newly created text in GIMP?

Use the Alignment Tool (shortcut key q):

• Select the text,
• Then choose the element which will be used for positioning (e.g., Image),
• Click on the horizontal and vertical center align buttons (second column in the first set of buttons):

This is actually dead simple but even simpler to miss! All you have to do is click the Align tool, then click the Layer over on the right side of your screen then go back to the lower left and click and an alignment button and hey presto. It works. Drove me mad for hours!

I've found solution:

1. On the empty art-board type text
2. Chose Alignment tool
3. Select text object pressing on it by left mouse key you'll see mini squares on the corners of selection
4. Use Alignment tool instruments to align text to art-board

I spent many time and realized that i missed 3-rd step. Select text object by clicking mouse, very important step. For me, Ctrl+A or other selections didn't work.