Hello. Recently I bought an iPhone 4 16gb from my friend. It is on iOS 6.0.1 (10A523) and also jailbroken (no ideas what kind of jailbreak it was). So however, I'm having a couple of issues with it, I believe it's software. So first of all, I wanted to watch a movie in youtube, downloaded the youtube app and when i try to play a video, it says 'playback error' or something like that, also I tried running mobile youtube website on chrome or dolphin, no positive results. When I turn it on with browsers, go to a video, circle just refreshes and then browser freezes for a few seconds, iphone freezes at the time to, after few seconds, it gets back to loading stage and after like 3 seconds of loading it freezes again. So that's the first issue, I cannot watch youtube videos. The second issue is with safari, mail and game center. So, when I turn on mail and safari, it just freezes, cannot do anything. I found that removing adblock fixes the issue, but I don't know how to remove it, however(I'm new to Apple, getting to Apple from Android, so it is very confusing to me). So this issue happens with safari and mail. Everything freezes when I turn it on. Another issue with Game center is, when I turn on the game center from menu it just shows loading.... Nothing else, just loading, wherever I press in it, still loading... Also, when I download some games, throught apps store, it says me to login to game center, but when game center pops up, I cannot cancel it, cannot create new apple account and when I type my current apple account and press log in, it just freezes on loading... again, nothing happens. Then the last issue, I guess. When I try to sync an app or a game from computer, I press install, it says will install, I press sync and after a bit, when it 'copies' the file to the phone, a notification on the locked phone screen pops up saying 'app failed to install' or something like that (I'll check what it says again). However everything is alright with music. Tried different apps, games, same. Also, I got three questions I guess. FIrst is how and what version of cydia should I install? Second, how to change notification (phone ring, SMS, other notifications) sound level, it just hits my ears too hard when I listen to some music with my headphones. And the third question is how to sync movies to TV. I have no ideas and all the guides from google shows example on the older versions of iTunes. Please help me as soon as possible, so I will know if I should get my phone back to my friend or it all can be fixed without any money investment.