Affinity Photo - super useful if you want Photoshop-like image manipulation

BetterTouchTool - amazing if you use the trackpad, plus it gives you Windows 7 style snap resizing

FCPX, Reading List, Stoic, Hemingway Editor, Xnapper :)

Pixelmator; Rogue Amoeba's Fusion; Alfred; DevUtils; Dash; Taio; Hook; GoodLinks

NobeOmniScope, Screen, Lattice, Hazel, Transmit, Mind Node

NotePlan, Paw, ProxyMan, CleanShot, 1Password are a few

Carbon Copy Cloner

DEVONthink