The Samsung galaxy ace runs the Android operating system so it therefore has access to the Android market. Also, as it is a Samsung made smartphone it also has access to Samsungs own app store ("samsung apps").
The Google Play Store and the Amazon Appstore carry about the same amount and kind of apps as Apple's App Store.
You buy the iPhone app
apple create the apps on iPhone
no you cannot use ipod and iphone apps on itunes, but you can buy the apps on itunes and put them on your ipod and iphone
Although iPads can download apps made only for iPhone/iPod Touch, the iPhone can only download iPhone or iPhone/iPad apps. Apps made only for the iPad do not appear on the App Store. Luckily most of these apps have an iPhone counterpart such as Angry Birds (iPhone) and Angry Birds HD (iPad only).
i don't know my does whats your model try restoring it after titanium backup (only backup apps)
The good news is that IPhone tracking is available and the ... you can look out for such as the GPS tracking ... iPhone Jailbreak News - iPhone Apps - iPhone ...
yes, but not all iphone 4 apps are available on the iphone 3gs/3g/2g becuase they are too high resolution apps, or need a front facing camera.
the galaxy tab it better then the iphone because it has hundreds of more apps than the iphone and its battey power is stronger then an iphones.
As long as your computer has itunes that is authorised on the same itunes account as your iphone, then it will automatically transfer all your iphone apps onto the computer
No you can not share iPhone apps.