Q: can't start 90% of my apps

See the reply in your other post:

https://discussions.apple.com/message/25965241#25965241

Your post indicates you have used Cydia, which is a software application for iOS that enables a user to find and install software packages on jailbroken iOS Apple devices. Since your iPad has been jailbroken, we can't help you in this forum. Best bet is to Google for answers.

Unauthorized modification of iOS can cause security vulnerabilities, instability, shortened battery life, and other issues

http://support.apple.com/kb/HT3743

If you jailbreak your iPad:

1. Your Apple warranty, if any is remaining, is canceled.

2. We can't help you in these forums.

3. Apple Support and the Genius Bar won't help you.

4. You can get a virus and malware.

5. You may "brick your iPad and have an $$$ paperweight.

What is Jailbreaking iOS? Should I do it?

http://tinyurl.com/mn5umca

 Cheers, Tom