Last year, my wife was complaining about missing discounts on items she she really liked, and planned to purchase when they were cheaper, just because she didn't checked the prices on the day the item prices dropped.<p>I liked the idea, and, with the help of a friend, we ended up building a browser extension. Turns out it's been more useful to me than to her.<p>I'm open sourcing the browser extension side, as I still don't know how the project will evolve, but in any case, browser extensions are too powerful to keep them closed source.<p>While this mostly works for Mexican stores, there are some US/worldwide ones, hopefully, it can be helpful to the community.<p>Thanks