If you need to use a custom font that is not available in iOS, you need to do the following steps.
1) Import the fonts into the Xcode project.
2) Add the fonts to the plist file.
3) Start using them in your app.
Open your project in Xcode and drag and drop the fonts that you need to use into the project navigator. I usually put them in a group called resources. Make sure that “Copy items into destination group’s folder” is checked and that “Add to targets” is also checked for the appropriate target.
The next step is to add the font to the plist file. Open your app info.plist file. It should be called “app name”-info.plist and it is usually under Supporting Files. Add a new row called “Fonts provided by application” it should be an array. Then add the file names of your fonts as string members of the array. My font is called Calibre-medium.ttf
At this point you are ready to use the font in your app.
For example if you have a UILabel *myLabel you can use the font with:
myLabel.font = [UIFont fontWithName:@"Calibre-medium" size:16];