So whenever I update my device when a new jailbreak comes out, I do it in the order that follows:
1. Backup & sync your device.
2. Restore & setup as "New iPhone/iPad/iPod."
3. Jailbreak & Install all previous Cydia tweaks (including AppSync so I get ALL of my apps synced to the device after the next step).
4. Restore from previous backup & sync data.
I do this so the settings for tweaks that have already been setup on the previous iOS installation (and are saved in the backup) are applied when I finally sync all of my data back to my device. Not all tweaks have their settings backed up in the iTunes backup, but some do, and this helps me have a few less things to re-configure to my liking after the restore/update.
I've always had great luck with this in the past; however this time, after I had completed the final step, I was unable to open Calculator, Mail, Safari & Weather.
Some of these I just can't live without since it's my work phone, and I think that goes without saying anyway.
If you find yourself in this predicament after the new Evasi0n7 jailbreak have no fear, there is an easy fix.
Follow the steps below and these apps will be back up and running in no time!
1. Open Cydia and navigate to the "Manage" section, then the "Packages" section.
2. Uninstall Appsync, then respring your device
3. Install iFile (if you haven't already)
4. Open iFile and navigate to /var/mobile/Library/Caches (or User/Library/Caches as they are the same, just a shortcut)
5. Delete the following 2 files from this folder
a) "com.apple.LaunchServices-054.csstore" (your numbers may be different, I'm not sure, but just find the similarly named file. There's only 1 like it)
6. Close iFile and reboot your iPhone (Don't freak out, if you did this right your AppStore installed app icons will be gone but reappear almost immediately)
7. Make sure that your previously-crashing apps now open properly (which they now should).
8. Open Cydia and re-install AppSync for iOS7
9. You are now finished. All apps should open and AppSync will be fully functional.
Note: Due to the compatibility issues with iOS7/Evasi0n7 & Mobile Substrate, if you had any tweaks installed you will have to also re-install Mobile Substrate & respring to get those working again after you reboot your device or install any tweaks in Cydia (this has nothing to do with AppSync, it is Mobile Substrate & it will be updated so you won't need to do this part in the very near future; but for now this is the workaround).
If this helped you with your issue let me know that too, and/or give me some love below!
IF YOUR ICONS DO NOT COME BACK OR THE STOCK APPS STILL DO NOT WORK YOU DID NOT FOLLOW THE STEPS EXACTLY, AND SIMPLY NEED TO DO IT AGAIN, MAKING SURE THAT YOU FOLLOW THE 9 STEPS EXACTLY IN THE ORDER THEY ARE LISTED. THIS IS VERY IMPORTANT OR THE FIX WON'T WORK
- DO NOT RESTORE UNLESS YOU HAVE A UNIQUE PROBLEM AND POST HERE TO TRY TO RESOLVE FIRST. THESE ARE ONLY CACHE FILES, SO THERE SHOULD NEVER BE A NEED TO RESTORE YOUR DEVICE!!
PP25 or 25PP or PPhelper (whatever you want to call it) also causes this issue and is not able to be fixed with this method on all devices.
If you have this installed and this tutorial is not fixing your problem, it is most likely due to PP.
Zeusmos & AppAddict are good alternatives I can confirm to be working through multiple reboots/resprings with no issues.