Here's a short list of services, tools, and software that we have had good experience with.
NOTE: We may receive financial compensation if you pay for one of these tools after clicking one of our links. However, we'd recommend all of this "stuff" whether we got paid or not.
DOMAIN REGISTRATION AND WEBSITE HOSTING
CallRail - We use CallRail for all our call tracking needs, and recommend it to any company with phone sales. CallRail makes it easy to track calls back to individual ads, but also offers call recording, routing, and some other handy features.
Bench - We use Bench for all our accounting. All the data and reports we need are here, everything is connected, and there's a real bookkeeper to help us if/when we need something. Jason would have more hair if he'd have found this company sooner...
SellerCandy - Managing an Amazon account often requires tedious back-and-forth with support, and for a fee you can make that problem go away. SellerCandy helps Amazon sellers deal with all the little "stuff" that makes you want to pull your hair out.
BeaverBuilder - The name is kind of dumb, but this might be the best theme builder available. While it's not as fancy or polished as builders like Divi or WPBakery, it also doesn't leave behind a bunch of gunk code if you decide to switch themes.
We love these free software tools.