We have detailed walkthroughs for Windows, Mac and Linux (Raspberry Pi)
We have also paired it without difficulty to iOS devices such as iPhone and iPad (any version) and an Android tablet but don't have a detailed walkthrough. Check your device's documentation on how to pair a keyboard. It's usually really easy and just requires turning on BT and then scanning for the powered up module.
You only have to pair once to your device. After that, it will auto-connect.
If you ever have difficulties with auto-connecting, especially if you do a system update or upgrade, just follow the pairing procedure from the beginning. It only takes a few minutes.