I was looking for an affordable alternative to super expensive keyword tools like ahrefs.com, as I started a website project as side business and I didnt want to invest lots of money in the first stage. (my main job is at a SEO agency, so I know the top tools for keyword research to compare this one with)
I discovered RankAtom because it was featured in Appsumo's 'SEO' category and gave it a try with a portion of scepticism that I always bring onto the table when testing a new software.

To be honest: I was super surprised how good and effective the Keyword research with his tool is. It includes many of the most useful metrics and really valuable and useful filter options. I also like the function that shows the domain rating of the top competitors for a keyword. Usually you can check that when just looking at the serps, however its a nice feature and shortcut to have it here and simultaneosly seeing the competitor domain rating.

The keyword rank tracker function is an useful addition, however, I already have more keywords to track than I can track with my purchased TIER1 plan from Appsumo.

I can recommend this tool absolutely and I will probably upgrade to a higher plan in the future (also depending on my business growth:-)

Just a small feedback: A nice future addition would be to have some mouseover texts with short definitions of the metrics for example in the keyword research interface. Some of the abbreviations like L.DA you understand contextually, some other like KGR not. (but I will figure out :-)