Even though Rezence is poised to become a wireless charging competitor to Qi, it isn't the only rival in town. WiTriCity has been in the cordless electricity biz since at least 2007 -- having partnered up with Toyota for charging its cars for example -- but hasn't really made a real consumer play for handheld devices just yet. That changes today, however, with the company's first reference design that pairs an iPhone 5/5s sleeve with a wireless charging pad. Like Rezence, WiTriCity uses magnetic resonance to charge compatible electronics, which means the pad can be installed underneath tables or other surfaces and the phone can still be refueled no matter where you place it. Of course, the sleeve is just a proof-of-concept and is not meant for sale, but WiTriCity hopes that this idea will prompt manufacturers to leap to its side. Whether or not this will compete against the likes of Powermats however, remains to be seen.