Note: free converting FLV to MOV is just part function of Emicsoft FLV Converter which is distributed by Emicsoft Studio.
Step 1: Free download FLV to MOV Converter and install it.
The interface is like the following:

Condition1: you already have flv video files on your computer.
1. Click file button, choose the flv video you want to convert
2. In output format, Choose quicktime (MOV).
3. Click start convert FLV to MOV.
. For More Information See this Guide: How to download youtube videos