Simple pinch-zoom category for UITextView.
Code works with and without ARC.
Library can be added to a project using CocoaPods.
Usage:
#import "UITextView+PinchZoom.h"
//...
UITextView *textView = [[UITextView alloc] initWithFrame:self.view.frame];
[self.view addSubview:textView];
textView.zoomEnabled = YES;
textView.minFontSize = 10;
textView.maxFontSize = 40;