Please tell me where I can download Fairy Tail the movie ending song-Zutto Kitto(Aya Hirano) to my mobile!

你 can find all Fairy Tail songs (OP, ED, Character Songs, etc.) here:

link
Just click the download link and wait to skip the ad.

If 你 just want that song:
link

These will download it to your computer. Then all 你 have to do is connect your mobile to your computer in anyway that 《金装律师》 你 to transfer the file. Cable, bluetooth etc.
I'm hoping your phone is not very old and is capable of doing this.