DGee5187 The app is called LED DMX. It works very well.

DGee5187 According to the specs, each strip is rated at 4.8 watts per meter or 400 mA. A 5M strip requires 2 amps. Using two strips would require a supply of at least 4 amps and I would use 5 amps as a minimum. Don't connect anymore than 10 meters or you risk overheating of the copper traces and dimming of the LEDs. Note that this strip uses separate red, green and blue LEDS. This means that if you want just want red, there will be two LEDS that are turned off in each section, along the length of the strip. I prefer the SMD5050 strips as each LED can be red, green or blue at the same time. In this case, each LED along the length of the strip will be red. The SMD2835 strip has separate red, green and blue LEDS spaced equally along the length. The SMD5050 strip has RGB LEDS spaced equally along the length of the strip, just to recap.

DGee5187 The difference in diameter between the two lights is only 3 mm so yes it should fit.

DGee5187 You can't sync two separate lights together. The only way this would work is if the two lights were connected to one controller.

DGee5187 The speed is adjusted from the power supply input between 12 and 24 volts DC. If you watch the video clip, you will notice the speed change as he adjusts the voltage up on the adjustable power supply.