How to put custom ringtone on iPhone 4?

I have an iPhone 4 (not 4s) and I want to put a song as my ringtone, but I don't know how. I downloaded a ringtone maker app and made one which I converted to the ringtone format but I don't know how to put it on my phone to use as a ringtone

Added (1). Thanks guys! Where's the 'Tone' tab? I've looked everywhere but I can't find it

You have to download the song on your computer. Then you'll have to put it in iTunes and in the "Tones" tab. Then Sync your iPhone and there you go.

You either need to email the mp3 to your email address or download it using itunes.doesn't it have these features? Do it have the email feature? If not, then go to itunes.click on your phone, and then click on the apps tab.scroll all the way down, and you should see the ringtone maker app there ok

1) Go to the App Store
2) Download the App Ringtones
3) Make sure the song you're wanting to use is in your iTunes and synced to your iPhone
4) Open the app Ringtones
5) Select the option use from iPod Library
6) Select the start and stop points of the song by dragging the selection bars along the course of the song
7) Trim it where necessary (by dragging each end where you want the song to be started and stopped) Can only be less than 30 seconds
8) Click on the save button (looks like a floppy disk
9) Plug your iPhone into iTunes
10) Go to file
11) Create new folder
12) Label it ringtones (it'll automatically rename it Tones)
13) Go to your iPhone under Devices
14) Click on Apps
15) Scroll down to file sharing
16) Click on ringtones
17) Click on the ringtone you just made
18) Click on Save To (I'd recommend your desktop)
19) Drag that file that's on your desktop into the Tones folder
20) Open the tones folder and drag that song onto your iPhone that's in the devices tab
Sync your iPhone