Am I allowed to disagree with all of you? Why is such a big deal if the taps are on top or bottom? Honestly, unless the app is badly designed overall, I just don't care where they are positioned.
I look at the original Instagram and your mockup and they are both fine to me, in a general way. However, there are details on the original design that I prefer over your mockup and vice-verse.
For instance, I dislike the flat look on your mockup, I just don't like it. For the same reason I don't like Holo. In my personal opinion, it just makes the design looks boring. That's the reason I really don't care about Windows Phone, those tiles and the flat look it's just fugly. And also the reason I'll probably never buy a Nexus phone.
The brown ActionBar is not my cup of tea either, I would prefer it blue, like in the original. And I also believe branding is important. I would never design an app with different coloring on different devices. Assuming the app was unique on Android, I wouldn't mind the brown if it was not flat.
But I do like what you did on your mockup with the colorful tabs, I think it's a really nice touch. Specially since they reflect Instagram's branding/icon.
But this is just me. I know I'm in the minority and I'm not here trying to convert any of you to my point of view. I just wanted to share my opinion. I don't mind apps like Instagram (design wise) as long as they are well designed and functional.
For instance, take a look at the Foodspotting app:• iOS: http://itunes.apple.com/us/app/foodspotting/id350727118?mt=8• Android: https://play.google.com/store/apps/details?id=com.foodspotting
I don't know if this app's functionality and usability are any good, I haven't installed it. I'm judging it's design by the screenshots.
They clearly look the same app and use the same design elements on both OSes. Is that a bad thing? I don't think so. In my opinion, the app looks gorgeous on each OS. I think there are elements here and there on each version that distinguishes the app from each OS.
Is Foodspotting really that bad on Android? I would assume most of you think so, judging by the comments here and everywhere else. Well, I don't. I think it's a pretty well designed app and I which Android had more apps as polished as this one.
To finish, and I can't stress enough that this is my opinion of course, if there's anything wrong with badly designed apps in the Android community they are not apps like Instragram or Foodpostting. But things like below:
It's because of things like these that Android is constantly compared to iOS and not the other way around. Overall app quality in iOS is pretty good, Android not so much. You guys are fighting pointless battles with tabs on top vs bottom instead of fighting that ugly trend on Android. Where most apps are just fugly.
Again, this is just me. And sorry for the long comment...