Everyone works in different ways and employ different tools to do the things they want to do. Here’s my curated list of tools I find I keep coming back to.

Development

Tower
The best Mac GUI git client I’ve tried.

CocoaPods
Third party code dependency manager.

Dash
Awesome documentation browser. Handles many languages and doc sets, but I use it primarily for Cocoa.

SimPholders 2
For finding and inspecting the contents of your app in the simulator.

iExplorer
For inspecting the contents of your app (or others) on-device, this is a great tool.

mogenerator
If you’re working with CoreData, you should be using this tool to abstract your object classes.

Fabric
iOS crash reporting, usage statistics, beta build distribution, and more.

Cocoa Rest Client
A simple GUI alternative to curl for testing ReST endpoints.

Cocoa JSON Editor
Super nice GUI tool for creating and editing JSON files.

licecap
Create animated gifs. Really nice for quick app demos on github.

Accessorizer
Great timesaver for generating boilerplate Objective C code, though Objective-C’s language updates have made this tool less useful than it used to be.

General

1Password
A secure vault for passwords, credit cards, passports, etc. Seriously the first thing I install on a new device.

Dropbox (referral link)
Secure online file storage and sharing. The second thing I install on a new machine, primarily to sync 1Password vaults and other app settings.

BBEdit
The text editor. I’ve been using this since… well since I can remember. It does it all and doesn’t get in your way. Installed almost immediately on a new machine.

Little Snitch
Basically a firewall for outgoing network connections. Probably the fourth thing I install on a new machine.

Quicksilver
A keyboard activated launcher and action performer (hard to describe). It is kind of like spotlight, but with more customizability and functionality.

Pocket
Bookmarking and reading app. Desktop, iOS, and web. A great way to keep hold of the gems one finds while surfing, Twitter, etc.

Soulver
Awesome calculator for problem solving.

Yummy FTP
The best FTP/SFTP Mac GUI client I have tried.

Knox
Simplifies creation and management of encrypted disk images. Everything that doesn’t go in 1Password goes in here.

Lingon
A GUI for creating and managing launchd configurations.

Name Mangler
Rename batches of files via a nice GUI.

Tweetbot
Twitter client for Mac and iOS.

Slack
Team collaboration and communication tool.

Airmail
The best, but not perfect, email client I have tried since giving up on Mail.app.

Backblaze (referral link)
Offsite painless backup solution.

Bartender
De-clutter your menu bar. This manages all the little menubar warts that seem to show up with various tools. Keeps things nicely tucked away, but accessable.

BetterTouchTool
A tool for configuring your interaction with a mouse or trackpad. Basically it allows you to program various gestures, clicks, taps, etc. to do any number of things.

cd to
A great little app which you install in your Finder “shelf” to open a terminal window at the current Finder location. It’s a huge timesaver if you are moving between the finder and Terminal a lot.
There’s an updated Yosemite icon (from https://github.com/jbtule/cdto/issues/9) which you’ll most likely want too.

CreateTextFileHere (shameless self promotion)
Another little app which sits in your Finder “shelf” to create a text file at the current Finder location. Created by yours truly.

Degrees
A little weather widget. I use the Mac menubar version. It’s nice and unobtrusive.

The Unarchiver
Far better tool than Mac OS X’s standard unarchiving tool. It handles so many more file formats.