Pleco runs on Android devices so you shouldn’t have an issue running it on a Galaxy II. It didn’t have the OCR feature until recently but that should work also. I think the developer himself said that it works better on iPhone though so that might be worth consideration if that’s an important feature to you. To me, OCR is the most incredible feature of Pleco and is a must-have. If you don’t know it is, read this.
Pleco aside, I personally think the iPhone is a better option. If you’re looking for something that competes with the iPhone though you should consider the Galaxy III. Personally I’m not really a big fan of Android though.