I've seen a few comments about issues on devices that do not meet the game's minimum requirements.

If your device is not supported you are likely to experience more crashing and freezing issues, if you're even able to play at all.

If you contact Support about an unsupported device, they will simply tell you your device is not supported, so please save everyone's time and do not email Support about any issue unless you have a supported device.

In general, Android and iOS devices manufactured in the last 3 years should work. We also recommend a minimum of 1gb of RAM on the device.

iOS supported devices:

iPad Air
iPad mini with Retina Display
iPad with Retina Display
iPhone 5 and above
iPod Touch 6th generation

Android required:

OS 4.1 or higher
RAM 768 MB or more
Resolution: 800 x 400 or higher

FAQ article: What devices are supported?