REVIEW IN PROGRESS: MORE COMING SOON
Firstly a kind of a warning: this is a pretty advanced and specialized audio tool. If you're the kind of person who just loads up a load of instruments then loads up a bunch of effects to slap down on them, twiddle the knobs, adjust the faders until everything sounds good then call it a day (the kind of person I am really, but I'm trying to learn and grow beyond that) then this VST is going to be not much use to you.
If you're the kind of person who is comfortable doing sidechain compression for example and hence messing about with the audio routing of your DAW then you probably in fact already know what a gate effect is and whether you need one.
Given that to get the most out of the plugin you're going to have to know how to do audio routing in your DAW anyway I'm not counting the following observation/advice as a warning, but it needs to be said that if you plop an instance of G8 into FL Studio you can play around with the knobs and buttons on the effect all you like, it will have no audible effect: you will continue to get the whole unaltered signal coming through. Compare this with Ableton Live where plopping down a G8 into your track will leave you immediately able to hear the gate's effect and play with all the settings.
Here's what you have to do in FL Studio to be able to hear an effect: pop a G8 instance into an empty mixer channel. Click on a mixer channel with an instrument or something in then right click on the little "send" up arrow at the bottom of the channel G8 is in and select "sidechain to this channel only". This will route the audio from the instrument to the channel with the G8 effect in and also break the send from the instrument channel to the main channel. If you don't do this and do a normal send you will still be able to hear the full, unaltered instrument and thus won't be able to hear the gate effect.
Now go into the G8 GUI, into the settings then on the "Processing" tab, right click the 1. 1/2 box on the left and select your input channel by name. On the right you can right click the outputs 1. 1/2 and 2. 3/4 to two free channels: insert 100 and insert 101 (I think this is just the default setup and you probably can send to any channel).
Now finally after all that you will have two channels, 100 and 101, one of which carries the gated signal and the other of which carries the rejected part. You can switch these by using the "flip" control on the plugin.
I wrote out the procedure for FL Studio just so it's clear that you have to get your hands dirty with virtual cabling!
--review in progress-- coming next: actual description of gating effect