Some frame grabbers work only on PC, some only on Mac, and some (like Dragonframe) on both. What computer are you using?
I tried Framethief (for Mac) a few years ago, it worked, but even then it hadn't been updated for a while so I doubt it would run on the more recent versions of OSX.
Lionel Orozco did a summary a few years ago of all the frame grabber software, both free and paid, so many of these might not exist any more, but you could have a look: http://www.stopmotionworks.com/stopmosoftwr.htm There are links to each site, so you could see if they are still around and if they would work with your camera and computer.
The only free one I have tested recently is Stop Motion Studio on an iPad, which also runs on phones - it could be set up next to your Nikon so you use it to gauge your moves, while capturing the real images on the Nikon using a remote shutter. But that's a pretty clunky work-around, similar to what I used to do when shooting on film before 2004, with a video camera next to my Bolex. Better than nothing, but there must be something that runs on your computer. These days I capture with Dragonframe on an iMac.
I used CorelVideo Studio 8 on my PC and it has a very nice live capture that has camera control and onion skinning. HOWEVER it may not work with Nikon cameras. I contacted tech support and she said no list exists of supported cameras. In watching Youtube videos that demonstrate the software you can see in the comments that Nikon cameras don't always work.
They have a free 30 day trial and after that the software is $70 USD. I also use the software to edit my family videos.
I just looked up the Helium Frog website, they were planning a version 3 with support for Canon DSLRs, but it hasn't been updated since 2012. I never tried it because it is for Windows 10, and I have a Mac. I suspect that the free ones will often be designed for use with webcams or video cams, and you might need a paid program to work with Canon and Nikon DSLRs.
If you are using a PC, Stop Motion Pro Eclipse is a good professional frame grabber, priced at $185. (At least that is less than the $395 for Dragonframe.) I used the previous version until my old PC finally died. They had some company working on porting it to Mac OSX for them, but are still waiting for results, so if you use a Mac you can only use Eclipse by installing Windows as well. I'm happy working with both Stopmo Pro and Dragonframe, they both work well with Canon and Nikon DSLRs and every pro film I've worked on in the last 5 years has used one or the other. SMP also do a cheaper version for students/hobbyists at $75, but that is with a lower resolution.
Animator HD professional version - price for me shows up in Australian dollars, at A $151.39, which is somewhere around US $115. It runs on Windows. The Home version is only A$29, but works with a maximum size of 1920 pixels wide. I'm used to shooting and saving larger than that, then cropping or scaling down to HD. Also it won't capture RAW images. You have to go up to the pro version for that.
iStopmotion is another one for Mac that seems to be around still: https://boinx.com/istopmotion/mac/
It says it has support for DSLR live view, and costs $49. I haven't tried it.
Sorry, I see you said right up front that you need it to work on Windows, somehow I missed that.
Just found a software with another free trial period. I have never used this software but it came up in an article about Stop Motion software.
AnimatorHD for $60USD
It has a list of Nikon Cameras that it is compatible with but I am not sure if the D3300 will work.
I found a program called DIGICAMCONTROL.
Its not exactly a stopmotion program but it shoots live video capture from dslr's from nikon and canon. I use it on my Windows pc and then i edit all the pictures together in nch videopad.
OpenToonz is a traditional 2D animation that also supports webcam and Canon DSLR stop motion. It is free and open source.
Here is a free one that was just shown to me. It is cloud based, so you get 50MB up front. After you create a free login you have 500MB to use.