There is a review on this site:
all-gmat-cat-practice-tests-links-prices-reviews-77460.htmlPrice: 1 for $25; 3 for $65
Bottom Line: Definitely a good practice for Quant if you have some extra money to spend. Unfortunately some questions overlap with the OG 12. For more info go here
GMAT Club Member Comments: "GMAT Focus is expensive but worth every cent." "If you don't mind the price of them, I think the GMAT Focus tests are pretty good. The big advantage is that they probably have a more-updated scoring algorithm, so you get an idea of where you're actually scoring for Quant. And it seemed to me that the types of questions were more recent (harder than OG, if you're scoring at a high Quant level).But if I had only $80 to spend, I'd probably buy the
GMAT Club tests - you'll get 25 very good tests (with ~37 questions each) instead of 3 tests (with 24 questions each)." (Source)
Although the review reads well keep in mind that it only has received 3 out of 5 stars based upon 95 votes. I recommend you use it only after you exhaust the usual avenues (OG, GMAT Prep,
MGMAT etc.)
Hope this helps