Lesson learned, if you're going to "delete" Cydia, make sure you're not going to want it back.....
Assuming you only "deleted" Cydia, you can reinstall it via debian packaging. Download iFunBox for your OS, plug your device in, click on the iFunBox Classic Tab, open up the device tree to your device, and click on Cydia App Install. Drag this .deb file into it, and reboot your device.
If you're going to follow Youtube videos, make sure that the user is a respected user that knows what he's doing. There are many scams and shams out there, especially those that spread fake rumors and information. If you're uncertain, always bring up the question and get confirmation
Hollo Willerz2, now I have a problem. My iPhone 4S ios 5.1.1 can install tweak in cydia but it not work( not show in setting).
The first I want to use call record so I install audio recorder. After finished my phone get error( on and off, on off) then I decide to use semi-restore to fix it as I want to keep jailbreak. My phone is work and has cydia but the tweaks not work. Please help me.
If you used semi-restore, all tweaks are removed from the device. The residual icons and data may still be there. If you want your tweaks working again, you have to re-install them. As for Call Record, I'm assuming this records any incoming and outgoing calls. This is illegal under many federal laws around the world as it's an invasion of civil rights and/or privacy.
Yes. If you need more explicit instructions, they're available here. There is a GUI method that was implemented by the developer, but I advise against it as it is really buggy. A Terminal/SSH Command/MobileTerminal method is recommended.