I've been trying to buy this specific Ninja air fryer thing for my sister's birthday next month and I swear the price changes like every single time I refresh the page. One day it's $120 then the next it's $150 and then it says sale but it's still $130? I feel like I'm being tricked lol. I heard someone mention that there are like... little apps or things you can add to your computer that tell you if a price is actually good or if it's just a fake sale but I have literally no clue how that works or what they are called.

Sorry if this is a really basic question but I'm not super techy and I've never used a browser extension before. Is it like a separate program? Do I have to pay for them? I'm kind of scared of downloading stuff that might have viruses or steal my credit card info since I do all my shopping on that computer. I just want something simple that shows a graph or something of what the price used to be so I don't get ripped off.

Here is basically what I'm looking for:

• has to be free because I'm already on a tight budget for this gift (trying to stay under $150 total)
• works on google chrome because that's what I use mostly
• easy to read because big data stuff confuses me sometimes
• maybe something that sends an email when the price drops?

I live in Chicago so it needs to work for the US version of Amazon. I've got about three weeks before the party so I'm hoping I can catch a real drop before then. If anyone has a favorite or one that is super easy for a beginner to set up that would be awesome. I tried looking at the web store and there were so many options I just got overwhelmed and closed the tab. Is there one that everyone uses that is actually safe?