Hands-down the best perspective-correction app I've ever used. – SKRWT Review

Update: I’m thrilled to see this app being updated again! It’s been an indispensable image-editing app for years and I was sad to see it languish. Welcome back! [This is the perspective-correction app iOS has been missing. Now I won't have to resort to Adobe Photoshop for OS X whenever I need robust perspective correction.]
Review by James Baxter on SKRWT.