Favourite paid tools that are totally worth the investment?

I'm inundated with the amount of tools out there promising to help with SEO, creative, performance, CRO, time management, analysis etc, etc. I'd love to hear from others what tools you have spent money on which were a game changer for you, or at least you feel were worth the investment.
For context, I am still early days in my ecom journey with sales growing steadily up until April this year when my ad performance started to tank. My product is organic cotton ski and sports socks and my main market is New Zealand and Australia. Secondary is US, Canada and UK. Product feedback and reviews are excellent.
I'm keen to invest in good tools to assist me with growth, so hit me up with your favs!