Keep proper frame rate in apps in multi monitor setups

[PolyMeilex]

Current frame rate of apps is broken, most likely it's because of wrong send_frames usage.

• Single 60Hz monitor setup will cause apps to render in 60FPS
• Two 60Hz monitors will cause apps to render in 120FPS
• Three 60Hz monitors will most likely cause apps to render in 180FPS ? (Not tested)