To basically say what happens when you RNG, first save your game somewhere where you can catch lv. 50+ pokemon, so I use the Resort's Pond. Then make sure your poketch application is on #5. Then save the game, soft reset it. Make sure you check what time you pressed A on the Continue screen. Plug the time in the pc program.
Then catch a pokemon and enter its stats into the program, in this Magikarp. Then it will generate a number, lets say Happiness Taps: 87, this means I switch to the happiness app and tap it 87 times. Then it says Coin Flip: 2, that means 2 Coin Flip taps on the poketch.
Then just go to Solaceon and deposit the pokemon you want to breed shiny, get your egg and hatch it and tadah :D
RNG stands for Random Number Generator, everything in games are numbers and basically the program is helping you to figure the numbers out to do anything :3 The only one thing you need is your Secret ID, which can only be figured out if you check the IVs of a Shiny pokemon you randomly caught (not chained) or AR. I don't have AR and never will XD So a friend helped me out to find my SID.