Image via WikipediaSD Tools is a benchmark and SD Card ID utility for Android, and it's very simple. It shows you the microSD card's OEM ID, which will often help you identify the real maker of the card. It is not uncommon in Asia to see "fake" or "falsely labeled" cards, such as cards labeled as faster than they really are, or marked as more famous maker than it is.
For example, a class 2 card can be marked and sold as class 6, which costs quite a bit more.
Not only can you check the OEM ID, you can also run read/write benchmarks to really know the performance. You don't need this all the time, but you will sue it a few times here and there.
Rating: try it!