You can create your own keyboard buttons as you desire - the file you're creating should be a png. file.

1. Place the button you want to use in the right folder, according to the selected directory and name it aol\yahoo\gmail (according to the button you'd like to replace) . In the photo below, we created a "@hotmail" button and replaced it with the yahoo email button.

2. Open the Mirror Me software > Features > Email. The new (in this case - @hotmail) button will be replaced with the yahoo button.

3. Change the text according to your button customization: