About the Pokeradar:
As mentioned in the Custom Pokemon Shop, the Pokeradar can increase your chances of finding a shiny. However it's not as easy as it looks. In order to do so, you have to use the Pokeradar and see the same Pokemon 40 times in a row without running. MUCH HARDER THAN IT SOUNDS. You need to bring lots of Super Repels(Max Repels are ripoffs) and lots of patience. Usually, you have to go to the farthest patch of grass that shakes. STAY AWAY FROM THE EDGES. Those are the places most likely to break your streak. If you get to a point where you're not entirely confident you'll see the same Pokemon again, you can do what is refered to as "reseting": Walking another 50 steps and using the Pokeradar again. Doing this will not affect how many Pokemon you've seen so far. When you get to 40 Pokemon in a row and on, there will now be a 1 in 200 chance that there will be a shiny Pokemon will show up. Here is when you want to start reseting like crazy. After you get a shiny, I think that the counter resets and you have to see 40 again, I'm not entirely sure on this part. Hope this helps!