How to create wifi hotspot with ubuntu 16.04 and up

Go to Network Icon on top panel -> Edit Connections …, then click the Add button in the pop-up window.

 Choose Wi-Fi from the drop-down menu when you’re asked to choose a connection type:

In next window, do:

• Type in a connection name. The name will be used later.
• Type in a SSID  (whatever name you want to appear for wifi)
• Select mode: Infrastructure
• Device MAC address: select your wireless card from drop-down menu.
  

Go to Wi-Fi Security tab, select security type WPA & WPA2 Personal and set a password.password length should be of 8 or more.

Go to IPv4 Settings tab, from Method drop-down box select Shared to other computers

When done, click the save button.

When everything’s done, enable WIFI from Network Manager icon on the panel. It should automatically connect to the hotspot you created

Now you can search and connect the access point from your Android mobile and enjoy!

if you have disconnected and want to reconnect (reuse the wifi that you have previously created) click on connect to hidden wifi network  and then select desired name of wifi