Yes, you can use Apple Airpods with any Android mobile phones, which has at least Bluetooth 4.0 connectivity option.
The AirPods will begin charging as soon as they are in the charging case. It does not make any difference, whether the case lid is open or close.
Yes, you can use Apple Airpods with any Samsung mobile phone, which has Bluetooth 4.0 or higher connectivity option.
Yes, Apple Airpods are compatible with Macbooks.
Look past their offbeat design and you'll find that Apple AirPods' compact size and high convenience factor are a winning combination.