Problem updating apps on iphone 5s?

Hi, it's been a few weeks i can't update any apps on my phone! I click on the update thing and it says Sign- In required. I'm signed in. I don't understand.

You have to re-sign in whenever you lock your phone.

  • Will updating my iPhone's software delete purchased apps and songs? I'm going to update my iPhone's 6.1.4 software to ios 7 when it is released in a few days. Some of my apps aren't available in the App Store anymore so will the update delete these apps off my phone?
  • Will updating my iPhone apps affect my phone speed as how updating the Operating System (OS) will? Currently I'm using the iPhone 5s on iOS 8.3 I know if I were to update my phone to the latest OS I may notice some slowdown on my phone's performance, since it may not have the "muscle" to handle certain functions. Many apps now are optimised for iOS 9 and/or the 6th generation phones. Will my 5s' speed performance slow down if I update my apps? Will the app's performance slow down?
  • Will updating my iphone 4s iOS erase my apps? I have an update available to a version 6 for my iPhone 4s, I have the memory space needed but I'm afraid i might lose my apps and the data that is with em. Will it erase my apps? Or will they be there when the update finishes?
  • Problem with updating whatsapp? When I downloaded the first ever app on my iphone (whatsapp) my friend used her apple ID and now when I try to update it it asks for her password instead of mine which I don't know:/ what can I do? I don't want to delete the app and reinstall because I don't wanna lose my chats help She's on holiday right now and I'm trying to update to save my chats for when I get my new phone tomorrow:/