SD Card Tester is an Android app developed by samliu720 that allows users to test the speed of their phone's built-in storage and external SD cards. With a simple and clear user interface, this app is easy to use for anyone. It's an excellent utility and tool, especially for those who want to check the read and write speed of their SD cards.

One of the best features of this app is its support for read/write tests for different file sizes. This feature allows users to test the speed of their storage with different file sizes to get an accurate reading. Overall, SD Card Tester is a great app for anyone who wants to check their phone's storage speed quickly and easily.