Performance Optimization for Android

Here is the list of the performance optimization tips when developing Android applications:

• Avoid creating objects if you don’t need them.
• Avoid memory allocation if you can work without it.
• Array of ints is preferred than array of Integers.
• Two parallel arrays of ints are a lot more efficient than an array of (int,int) objects. Two parallel arrays of Foo and Bar are a lot more efficient than an array of (Foo,Bar) objects.
• Avoid creating short-term temporary objects if you can.
• Make your method static. Invocations will be about 15%-20% faster. It's also good practice, because you can tell from the method signature that calling the method can't alter the object's state.
• It's reasonable to follow common object-oriented programming practices and have getters and setters in the public interface, but within a class you should always access fields directly.
• Direct field access is about 7x faster than invoking a trivial getter.
• Use static final for constants.
• Prefer for-each loop.
• Declare fields and methods accessed by inner classes to have package access, rather than private access.

Read Designing for Performance article from Android Dev Guide to find more details and samples.

List also available as gist.