Yeah, I know about bangs, but on mobile they are cumbersome to use: I have to tap my screen 7 times to change from DDG to Google:

    1. tap DDG search bar
    2. tap space
    3. tap shift key
    4. tap "!"
    5. tap shift key
    6. tap "g"
    7. tap enter key

If DDG included a simple button, it would be 1 tap. Of course, I can't blame them for not linking to Google, but this way I will stick with Google.