Is hanzigrids.com Safe?

I home school my children. They are taking a Chinese course through flvs.net. The school recommended and supplied a link for pinyin download so they could do their work directly on the computer without having to copy and paste everything. Hazi Grids was also on the same download page as pinyinput. It has been a huge asset to my children's learning experience. When it comes time for them to do their writing, I copy and paste the Chinese character they have to submit for a grade into hanzi Grids. It will then convert it into a PDF file that I can print for them so they can have writing practice befor they submit for a grade. The children refuse to submit their writing assignments without it. IMPORTANT: It is $10 AUD currency. I use the USD. I contacted them via the website because of the currency issue. They were very quick to respond. They accept payment via PayPal so no one has to pay conversion fees through their bank or credit card company. They explained that currency rates change constantly, but PayPal will only charge you the current rate at the time of purchase. In my case, I only had to pay $8.64 USD to equal the $10 AUD. Very pleasant experience. This post was written 2 months after purchase.