Not the official one but the feel is same is Counter Strike 1.6. Its developers named it Critical Strike 1.6 or CS Portable. I was quite wondered to have CS on my phone. Nostalgia. But as soon as I got my hands on the game I realized that Shadowgun or BIA are better than it (in terms of UI). But still those guys have done the awesome work. Appreciated.
You will find the gameplay quite same as Counter Strike 1.6 therefore the game is not there in Android Market (G-Play Store) and App Store. CS Portable has been there for a long time but I have come to know about it recently.
You can download CS 1.6 file from their website(links below) and install in your android device or iOS device(Any: iPod touch, iPhone, iPad). There is no minimum system requirement as such (although they have mentioned that in their website). You can even play it on your Galaxy Y. Obviously, some phones are not supported.
Minimum System Requirements:
- Android 2.0+, iPad (any), iPhone 3GS+
- CPU 400 Mhz+
- Memory 128 MB+