If you're asking about the iPhone version, why did you create this post in the Windows Phone forums?
There are many ways to update the applications for your iPhone. Probably the most convenient way is just going into the "App Store" application, select "Updates" on the command bar, and select "Update All". Otherwise from that screen you can opt to go into each application and manually update each one.
Another way it to open iTunes up on your computer, Click in the "Apps" subsection of the "Library" and if you see "Updates Available" in the lower left-hand corner of the window then you can click on it. In the next window, you'll have a choice to "Download All Free Updates" or opt to queue each application one by one. Once your download queue has quiesced, then you can synchronize your iPhone with your iTunes.