WHen you are doing:
startActivity(intent);
just put:
startActivity(intent);
overridePendingTransition(animIn, animOut);
animIn and animOut are ints that you can just define in anim resources folder for example:
slideInLeft.xml:
<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
android:fromXDelta="100%p" android:toXDelta="0%p"
android:duration="@android:integer/config_longAnimTime" />
slideOutLeft.xml:
<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
android:fromXDelta="0" android:toXDelta="-100%p"
android:duration="@android:integer/config_longAnimTime" />
And when you want to return to the first activity you need to do the same but in finish method of activity:
finish();
overridePendingTransition(animIn, animOut);