How do you use the dowsing machine poketch app on Pokemon pearl?

You can't use a "dowsing machine Pokétch app" in Pokémon Pearl. There is no such app in the game.

Here's why:

* No Pokétch App: The Pokétch doesn't have an app for dowsing.

* Dowsing Method: In Pokémon Pearl, you use the Dowsing Machine item, not an app, to find hidden items.

How to Find Hidden Items in Pokémon Pearl:

1. Obtain the Dowsing Machine: You receive the Dowsing Machine from the Pokémon Fan Club in Jubilife City after completing the Pokédex challenge (catching 60 different Pokémon).

2. Equip the Dowsing Machine: Go to your Bag and select the Dowsing Machine. Equip it like any other held item.

3. Use the Dowsing Machine: The Dowsing Machine will automatically start searching for hidden items when you're walking around.

4. Follow the Arrows: The Dowsing Machine will use arrows on the top screen to guide you to the hidden item. The arrows will point you in the general direction of the item, and they'll become more frequent as you get closer.

Note: The Dowsing Machine doesn't always find items on the first try. You may need to walk around the area for a while before it starts giving you directions.

Let me know if you have any other questions about Pokémon Pearl!