which amp are you talking about in particular.
The HF-3s aren't terrible for their price they're pretty good, but the bass is shy.
As snag1e said these iems don't really require any amping, but rather the source is more important because iems well don't require much power to run. Putting that aside, if you don't care about the little bits and details that could improve your sound by 10-30% on low ends, then you would be fine with your android.
If you are planning on getting a 4s though, you could really just stop there for any source upgrades (portable)