If you need a permanent free solution for real-time pitch correction, several high-quality plugins offer similar "snap-to-key" functionality without the cost: MAutoPitch (by MeldaProduction)
You searched for because you want the sound of Waves, not necessarily the logo. Here is a signal chain to emulate the Waves Tune Real-Time using the free plugins listed above: waves tune realtime plugin free top
You can download a fully functional demo of Waves Tune Real-Time from the official Waves website. It lasts for 7 days and has white noise bursts. This is perfect if you need to track vocals for one weekend session. If you need a permanent free solution for
MeldaProduction creates "freemium" plugins that are incredibly powerful. This is perfect if you need to track
If you specifically want the Waves version, the best way to get it for "free" temporarily is through their official evaluation program: 7-Day Free Demo : You can download and use a fully functional version of Waves Tune Real-Time for 7 days. To do this, download Waves Central
Unlike Antares Auto-Tune (which is heavy on CPU) or Melodyne (which requires you to record first and edit later), does exactly what the name suggests. It corrects your vocal pitch as you sing, live.
A simpler, high-speed tool for that specific modern pop sound. Best Sellers - Waves Audio