If you updated last week to version 5.5 from the App Store, you already have the speedy check-in feature. Here's how it works:
When you view the list of venues to check in at, you simply long-press on the venue you'd like to check into and wait for the green bar across the top to go across your screen. You're instantly checked in, with no prompt for a shout.
Now close the app, put your phone back in your pocket (resist the urge to check Facebook, Twitter, and Instagram), and enjoy where you're at instead of wasting the experience by staring at your phone.
The new feature is a welcome addition. In the past I had covered ato speed up the check-in process on both iOS and Android, but it wasn't an ideal solution. This is a step in the right direction.