Create simple android nfc reader/writer

I want to create a simple nfc reader/writer for android. My plan is that when I open my app I can place an RFID tag on the back of my phone and get a choice to read or write to the tag. If I choose read I want the phone to show the information on the tag and if I choose write I should be able to write something to the tag.

I have tried to look into this and read other peoples code but I cant' make anything of it probably due to my quite limited java knowledge. I would like some pointers to where I can find more basic information and from there start with the reader part and add the writer when that's working.