The Galaxy Tab 7.7 and Droid Xyboard 8.2 were seen as tweeners in their day, but the 8 - inch form factor has since picked up mainstream popularity thanks to devices like the iPad mini. (pcmag.com)
Sproles, Cooley, etc were described as tweeners on the offensive side of the ball. (sbnation.com)
Tweeners like Clemons and Schofield are much easier to find. (sbnation.com)