Hi Sarah,
I have used both PIVATS and B Squared. I prefer B Squared as I find that it breaks down learning further than PIVATS. Saying this, I have not used PIVATS for about 5-6 years so it could have changed. The first levels of B Squared are very broad, just an FYI so we tried to break them down further. I have used both paper and online and prefer online to paper.
I know that B Squared also has a programme called EVISENSE which is the SEND version of an EYFS tracking system using and IPod, IPad or iPhone if I remember correctly. My previous school was looking into using it, but I did not get the opportunity.
Wishing you all the best,
Angela