It's not a standalone application.
If plugin doesn't work, try to install it to internal memory.
It's a plugin for c4droid, that allows it to compile C and C++ source code using GCC.
It contains gcc 4.6.1 with Bionic (Android libc). Source code hadn't been modified, so you can compile it yourself, if you want.
To use GCC with c4droid, you need root and 50MB of free space on sdcard OR 50MB of free space on internal memory (root is not required).
To install plugin, just install this application (after installing c4droid), press Install (to internal memory if you don't have root or to external if you don't have enough space on internal memory and have root), wait for unpacking and delete this application.