I just found out about this and turns out it's pretty easy to do.

1. Create a XML file and copy the following

   <?xml version="1.0" encoding="UTF-8"?>
   <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
   <plist version="1.0">
   <dict>
       <key>PayloadContent</key>
       <array>
           <dict>
               <key>Font</key>
               <data>
                   Base 64 String
               </data>
               <key>PayloadIdentifier</key>
               <string>font identifider</string>
               <key>PayloadType</key>
               <string>com.apple.font</string>
               <key>PayloadUUID</key>
               <string>B0DF5525-7120-406F-AC71-5A5BA59ECD82</string>
               <key>PayloadVersion</key>
               <integer>1</integer>
           </dict>
       </array>
       <key>PayloadDisplayName</key>
       <string>Payload display name</string>
       <key>PayloadIdentifier</key>
       <string>Pay load Identifier</string>
       <key>PayloadOrganization</key>
       <string>Font Profile</string>
       <key>PayloadType</key>
       <string>Configuration</string>
       <key>PayloadUUID</key>
       <string>0A35FE6A-C980-442B-9BD3-F44C67CA0D19</string>
       <key>PayloadVersion</key>
       <integer>1</integer>
   </dict>
   </plist>
   

2. Convert the font you want to install to base64 by executing the following command in terminal

   openssl base64 -in font_name -out output_file_name
   

3. Copy the base64 string to clipboard

   cat output_file_name | pbcopy
   

   and paste it into the XML file between the <data> </data> tags.

4. Open the XML from your iOS 7 device by sending it via email or uploading it to Dropbox or something.

5. Install the profile.

   

Now you can use the font in any apps that allow font selection, like Keynote for example.

Enjoy! ヽ(｡ゝω・｡)ﾉ