Playground: Draws a little view with a triangle point at the center bottom pointing down.

POIBottomPointingView.swift

//: Playground - noun: a place where people can play
import UIKit
import PlaygroundSupport

class ReminderView : UIView {
    
    let popupColor = UIColor(white: 0.0, alpha: 0.16)
    let drawingCornerRadius: CGFloat = 6.0
    let bubbleHeightRatio: CGFloat = 0.83
    let label = UILabel()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        commonInit()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }
    
    func commonInit(){
        backgroundColor = UIColor.clear
        
        addSubview(label)
        label.frame = CGRect(x: 10, y: 0, width: frame.width - 20 , height: frame.height * bubbleHeightRatio)
        label.text = "Something else should go here"
        label.textAlignment = .center
        label.adjustsFontSizeToFitWidth = true
        label.font = UIFont(name: label.font.fontName, size: 22.0)
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        label.frame = CGRect(x: 10, y: 0, width: frame.width - 20 , height: frame.height * bubbleHeightRatio)
    }
    
    override func draw(_ rect: CGRect) {
        let bubbleHeight: CGFloat = round( frame.size.height * bubbleHeightRatio )
        let pointWidth: CGFloat = frame.size.width * 0.07
        let horizontalCenter: CGFloat = frame.size.width * 0.5
        
        let context = UIGraphicsGetCurrentContext()
        
        
        //----- Path Drawing --------
        
        //Start at Center-top
        context?.move(to: CGPoint(x: horizontalCenter, y: 0.0))
        context?.addLine(to: CGPoint(x: frame.width - drawingCornerRadius , y: 0))
        
        //Draw curve around right corner, then down
        context?.addArc(center: CGPoint(x: frame.width - drawingCornerRadius, y: drawingCornerRadius),
                        radius: drawingCornerRadius , startAngle: CGFloat.pi / 2.0 * 3.0 , endAngle: 0.0 , clockwise: false)
        
        context?.addLine(to: CGPoint(x: frame.width, y: bubbleHeight - drawingCornerRadius))
        
        //bottom right corner and to the edge of the point
        context?.addArc(center: CGPoint(x: frame.width - drawingCornerRadius ,y: bubbleHeight - drawingCornerRadius ),
                        radius: drawingCornerRadius, startAngle: 0.0 , endAngle: CGFloat.pi / 2.0 , clockwise: false)
        
        context?.addLine(to: CGPoint(x: horizontalCenter + pointWidth, y: bubbleHeight))
        
        //Point
        context?.addLine(to: CGPoint(x: horizontalCenter, y: frame.height))
        context?.addLine(to: CGPoint(x: horizontalCenter - pointWidth, y: bubbleHeight))
        context?.addLine(to: CGPoint(x: drawingCornerRadius, y: bubbleHeight))
        
        //Left Bottom corner and up
        context?.addArc(center: CGPoint(x: drawingCornerRadius , y: bubbleHeight - drawingCornerRadius),
                        radius: drawingCornerRadius, startAngle: CGFloat.pi * 3.0 / 2.0, endAngle: CGFloat.pi , clockwise: false)
        
        context?.addLine(to: CGPoint(x: 0, y: drawingCornerRadius))
        
        //Topcorner and back to the top center
        context?.addArc(center: CGPoint(x: drawingCornerRadius, y: drawingCornerRadius),
                        radius: drawingCornerRadius, startAngle: CGFloat.pi , endAngle: 3 * CGFloat.pi / 2 , clockwise: false)
        
        context?.addLine(to: CGPoint(x: horizontalCenter, y: 0))
        //END Path drawing ---------
        
        
        context?.setFillColor(popupColor.cgColor)
        context?.drawPath(using: CGPathDrawingMode.fill)
        
    }
    
}

let mainView = UIView(frame: CGRect(origin: CGPoint.zero, size: CGSize(width: 600, height: 300)))
mainView.backgroundColor = UIColor(hue: 0.3, saturation: 0.00, brightness: 0.9, alpha: 1.0)

let reminder = ReminderView(frame: CGRect(x: 10, y: 50, width: mainView.frame.width - 20, height: (mainView.frame.width / 4.90) ))
//reminder.backgroundColor = UIColor.lightGray
reminder.clipsToBounds = false
mainView.addSubview(reminder)

PlaygroundPage.current.liveView = mainView