Frankly Google sheets was the best tool we used.

I like Atlas.TI. But: 1) it is geared towards processing of data, not so much the annotation of documents although you can do it. What is annoying is that if you code a set of docs automatically, you have do it all again if you add a document. That is not how a literature review works. 2) Very VERY slow when using a large number of documents. 3) No mindmapping visual capabilities beyond what logically extends from the coding, which is limited, see point 1.

I recommend looking at Dedoose software, which fits my needs better than any of the larger programs (Hyperresearch, AtlasTi, NVivo, MaxQda,) -- which I looked at and/or used extensively before switching over.  Why Dedoose?  It's user friendly, powerful, cross-platform, works great with team projects or individual projects, and can offer beautiful mixed methods graphs (quantitative variables that you use to describe your data compared with the qualitative codes you apply to the data).  I've been using it for years and also teach methods with it.