easy go to the department store in veilstone city, on the second floor on the left there is three people go to the person facing forward and she will give you the counter app (app: 11
you need to cheat to get them with an action replay.
get the Poke tech App Poke happyness
u click and hold the Pokemon with ur stylus
talk to a girl in the eterna city Pokemon center on 1F
Routes and Places: Solaceon Ruins, Stark mountains, Resort Area Wild Grimer and pick up using the dowsing machine on the poke tech
As you progress in the game, people will give you apps for your poke tech. they can show maps, caught Pokemon, time, drawing pad and more. to switch apps press the button on the touch screen on the right. yay!
from dawn ( choose right hand )
You get a special poke tech app and It shows you. The one were the Pokemon look like they are floating, you just touch them with your stialis.
when the battery is charged walk into grass and use it. the grass will rustle where Pokemon definitely are. if it sparkles then there is a high chance of finding a shiny Pokemon
Poke Tech 23,24,and 25 are all obtained through Nintendo Events. For a list of all the Apps go to: http://www.serebii.net/diamondpearl/poketch.shtml
It took me a while to find out, but here's what you do. Take you DS Pen, stylus, and hold it on the desired pokemon. You should see a heart or two if it likes you. If nothing happens, it doesnt like you. If it has 1, it sort-of likes you. If 2, it is close to you. Hope this helps!
just use your poke tech look for something that Haz a line going up and down.