When you making video or have class presentation with your android device, you need a pointer. I saw some guys use laser pointer but you can have a pointer in your android mobile or tablet too. what is better than mouse pointer, you can handle it really easy. To connect a computer mouse to your device you need an OTG cable.
The OTG cable help you to connect computer mouse to your mobile. just connect OTG to your mobile and connect mouse to another side of OTG.
By watching my video help us to make better project and shire it with others (it's really effect).