I've been using Wikibuy along with Honey for some time now, and while both are very useful, frequently Wikibuy comes up with the lowest price.
it's not perfect, like many such tools it can get the product search wrong and return a low price for a different product or size, but it doesn't happen very frequently, and it is easy to report such errors.
I'd hate to be stuck with just one shopping add-on, but this is one of my top candidates.
I enjoy using it on Chrome. Unfortunately everytime I try to add it to firefox, I get a failed to download message and check my connection....Its not my connection since I can get to every website I try just fine with the existing conection.
I like wikibuy and have used it for price comparisons, guidance and whatnot. However, I would have given a 4-star+; the problem is that over that last couple of months wikibuy doesn't appear on sites like Best Buy and many others. In this arena, there are many sites that seem to have "blocked" the ability to use it. I whitelisted wikibuy, bestbuy, lowes, etc. It worked with Best Buy with the whitelisting...then it didn't. It was a temporary fix that no longer works in tandem with the sites I visit. That's not to say it's not beneficial, but at this point I have to go the wikibuy site and manually add items (using product numbers) to my 'watchlist'. Working in IT, it's surely not wikibuy's inherent issue...it's that it must be being blocked in this technology-ridiculous world.
Thought I'd give it a try but didn't expect much. I've used it for 2 days and thus far saved about $50-75! Several items I got a $20 discount on, one of those I purchased on Ebay because it was $20 cheaper than Amazon. Amazon is my go to for purchases. I used to check with several other sites to be sure I was getting the best price [Walmart, Best Buy, Ebay] and it would appear that this app does that comparison for me....that's a lot of time saved. So we shall see over time, but right now I'm lovin' it. Hopefully I can come back and update my review later....