If you're using an iOS device (iPhone, iPad, iPod Touch):
All you have to do is go to the App Store and tap Updates. You should see a list of apps that have updates available. If you see Checkout 51 in that list, tap the update button on the right. If you don't see Checkout 51 in the list, then you are up-to-date!
If you're using an Android device:
Often Android devices are set to automatically update and don't require users to update their apps themselves.
To check whether your device is running the latest version of Checkout 51, follow these steps.
1. Go to the Play Store and click the three dots top right corner.
2. Select My Apps from the drop-down menu.
3. If Checkout 51 is listed under the Updates section, click on it. If you don't see Checkout 51 under the Updates section, then you are up-to-date.