You only wanted Cydia? But Installer is also good too! So I'm going to show you all an easy way to get Installer without having to restore.
1. First off, you will need to download OpenSSH from Cydia.
2. After you've done that, download PwnageTool. Right click on PwnageTool, and press "Show Package Contents."
3. Navigate to Contents/Resources/CustomPackages. You will see Installer.bundle. Again, right click, and press "Show Package Contents."
4. Navigate to files/Applications. You will then see installer.app. It has a cross in the icon because it is unsupported on the Intel Architecture. Leave that window open, we are now going to CyberDuck, an FTP client.
1. On your iPhone or iPod, go to Settings, Wi-Fi, and click the blue arrow next to the network you are connected to.
2. Take note of the IP address. Open CyberDuck, New Connection.
TAKE NOTE OF THE FOLLOWING:
Change FTP to SFTP
Add the IP address that u took note of.
Username: root
Password: alpine
Open the /Applications and drag Installer.app into it.