I love all tools cited here, although never heard of a few before, such as Asana and Todoist. Eventually I even use them, but...
As a Computer Engineer, mostly I use apple and google (including chrome, android, etc). Really. I'm also struggling a bit trying to use discourse instead of zendesk. And finally starting to use GitHub, which I should have done long ago. Nothing really replaces being able to google for whatever I need. It is just awesome, and completely understated. And please do yourself a favor and get Inbox, as gmail is so old now! 
I've been using paypal, but that should soon change to bitcoin or w/e. Doesn't matter. Same thing for text editor. TextEdit, Smultron, TextWrangler and Atom are the current ones, but those change a lot over the years.
Pocket is freaking great, but not used for freelancing or working in specific. Dropbox is one of the best, but I never used it for syncing my work for my own or for sharing files with a client. I usually go for google drive if needed. Even LastPass I don't really need for my work as freelancer.
I guess what I'm saying here is I've never really needed any single tool as freelancer other than the most basic ones.
Except...
I'm still missing a good public ticket manager. Zendesk was good enough as a private one. I feel like Asana is way too overkill for a single freelancer, and still doesn't look like it offers anything public like I wished. I've also seen another one other than Trello on those lines "like google wave" (which was much more like gw, btw), but I can't remember the name. It's not sandstorm, and it's all private only as well. I guess it's too much of a "new" concept or maybe it is just a broken idea I've had.