I searched a lot but I couldn't find a post about that.
I want to use some button to send input to my android phone and trigger action in my app.
What do I need in order to achieve that?
AgMrs:
What do I need in order to achieve that?
An Android app that can receive commands from an Arduino via bluetooth.
I know that.
I was talking about which component do I need, what bluetooth module should I use?
Is the Arduino Uno good for that or I would need of the ADK version?
AgMrs:
I know that.
Good. I assume you have got that sorted then?
I was talking about which component do I need, what bluetooth module should I use?
Is the Arduino Uno good for that or I would need of the ADK version?
A cheapo HC-05 bluetooth module is fine and so is a plain-vanilla Uno. I don't know anything about the ADK and I believe there might be good reasons for that, but I understand it can connect to Android via USB, and is no better at using Bluetooth than other Arduino.
Here is some background on basic Arduino<>Android via Bluetooth.
http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino
but this is not about controlling an Android, that is what you already know about, this is just communication.
Check out http://www.forward.com.au/pfod/ArduinoProgramming/UnoStarter/index.html
for controlling arduino from Android via bluetooth. Simple plug and play.
For your own Android menus check out pfodDesignerV3
which is a tutorial on using the free pfodDesigner Andriod app to design and format your own menus and then generate the Arduino sketch that servers up the menu and handles the results, using pfodApp
Here is an example menu build with pfodDesigner. No Ardroid programming required
This link is dead 
@drmpf
I think @AgMrs wants to control Android using the Arduino, not the other way around, so unless @AgMrs is not describing their project correctly, I don't think your Android menu app will do what they want.
I want to use some button to send input to my android phone and trigger action in my app.
What do you mean by
my app
Did you write your own Android app ? Please give more details.
If you have written your own app, you will need to implement something like a BlueTooth serial terminal inside your app, so that the BT serial module can send characters to your app, and your app can take the appropriate action
rogerClark:
@drmpf
I think @AgMrs wants to control Android using the Arduino, not the other way around, so unless @AgMrs is not describing their project correctly, I don't think your Android menu app will do what they want.
I think you are correct, my bad.
Controlling Android from Arduino is a more difficult and does need Android coding.
No worries. Your app looks cool, but I've not had time to install it on my Android tablet.
I've been messing around with some RS232 based Wifi modules, and it looks like your menu's may be compatible with them, i.e if you menu's can connect to an arbitrary port at a specific IP address and then send data, which is received as RS232 by the Arduino
With @AgMrs, as every, people don't seem to realize that they need to post a reasonable about of information about their project if they want to get a decent answer.
rogerClark:
if you menu's can connect to an arbitrary port at a specific IP address and then send data, which is received as RS232 by the Arduino
Yes pfodApp can connect to specific IP and arbitrary port. I use Fio V3 with a RN wifly (Xbee format) module.
see A Simple WiFi/Arduino pfodDevice™ with 128 bit security
for a tutorial. pfodApp also has optional 128bit security.
also see Setting up RN-42XV Bluetooth and RN-XV Wifi XBee format modules on SparkFun's FioV3 Arduino board. for how to configure the wifly.
drop me an email if you need help with these.
rogerClark:
This link is dead
Sorry about that, try this........
http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino