This very simple app displays what kind of charger you're connected to :
Fast Charger, Normal Charger, or USB charger,
and how many milliamps are being delivered.
This helps me determine which charger in my house is the fastest, and helps me evaluate how good each charger is.
Currently it is known working on the Samsung Galaxy S2.
It DOES NOT work on the Samsung Galaxy S3.
If you know how to measure battery charging milliampres, please help on the forum topic:
V2 - Minor fixes to support more phones. Still can't figure out the S3. Needs testing.
V4 - Minor fixes, some numbers weren't numbers and flagged a FC.