The TDA2822M is a monolithic integrated circuit in
8 lead Minidip package. It is intended for use as
dual audio power amplifier in portable cassette
players and radios.
very handy chip in use and low cost
In this project its only one channel (mono) because i didn't have the room to add few capasitators more. the audio jack makes it for the both channels but from the chip its only on one channel (you can make stereo by using both channels and using two microphones or bridge the channels)
Now when you have the circuit board ready. start soldering the parts on to it by copying the layout from picture 3 (if you have something to say about the layout please do say it. i'm not perfect about it and it might have lots of work to do about it, but for me it works just fine).
In the layout at the speaker part you put the audio jack.
Remember to fit the circuit to the phone after every added component that it fits in the phone.