need help identifying the most important parts in blu r1 motherboard

Hello guys, recently my blu r1 power button stopped working and I took the cover off. So I was able to identity the power connection to motherboard right away; however, the rest of the components are not so easy to spot as in a computer. So I'm posting a picture of my blu phone here, so the community can help me identify the most common element on the motherboard eg: CPU, Internal Storage, Antenna, sensors, etc..

Thanks for the help