Blink Text with JavaScript
It doesn't look very complex to me but the variable names could use some attention, as they're not very descriptive. I'd suggest:


textHidden instead of flag
timesBlinked instead of i
targetElement instead of divID (it's not an id anymore, but the element referred to by the id)


I would also toggle the element visibility instead of removing and adding the text for several reasons, one of them being that removing text can also change the element's height and/or width, which can cause problems with the layout.

if( textHidden ) {
    targetElement.style.visibility = 'visible';
} else {
    targetElement.style.visibility = 'hidden';
}

textHidden = !textHidden;  // flip the flag