You can easily use http://www.wireshark.org/ to track what the software does. You'll fine nothing suspicious. Beside the fact that open source is not equatable to "safe", this is a common prejudice.

After this facts, there is another one, very important: We are not hiding behind aliases and nicknames (like many open source authors does), but a registered company. Take a look at https://coinbrother.com/

If this list of counter-arguments doesn't change your mind, you can decompile the software (takes not even 10 seconds), since it's Java we use to write this software.