Pros: It is a small size and easy-to-use FLV Player.

Cons: It installs where it wants - no options.

Sothink FLV Player is a nice choice to play flv videos. I've used this program a couple times, it performed well. See a screenshot of this program: 


The installation is straightforward. However, the destination location could not be changed easily, there are no options for us to select. Sothink FLV Player is free of charge as well as mulware.

It supports flv video files encoded by different codecs, so it could play all the flv videos downloaded from Youtube or other video websites.

Sothink FLV Player supports full-screen mode. Just like you watch mpeg videos with media player, double clicking the player window, it will toggle full screen mode.

It is friendly that Sothink FLV Player automatically adapts window size to the flv video.
And if you don't like that, you could resize the FLV player window to meed your need.

There is also a powerful function - open FLV file from URL directly. I've tried, however, it took me a lot, and finally, the video didn't show.

Conclusion:
Sothink FLV Player is a cute program; with its help you can enjoy downloaded flash videos offline at any time you like. I wish in the next version, it could remedy the installation bug - enable us choose the destination location to install it.