The first question is why do you want to turn off gmail less secure apps setting. Okay there may be lot of reasons. May be you want to use an app that google does not like. But before turning off it. Let me tell you that this feature is designe to protect your data. If you use any such app which is not approved by google. You are responsible for this. Because there are many spam apps also available in the world.
To Learn how do gmail less secure apps turn off
How do gmail less secure apps setting disable learn step by step. Go to your web browser and log in your google account. After it click on your profile and select my account. Now a My Account page will be open. Click on sign in & security option and select the option connected apps & sites.
Connected apps & sites tab will be open and you will be see a option Saved password. Below the saved password option you will see the setting option for Allow gmail less secure apps. This option is ON by default.
You need to OFF this option.
After do it, you can access your google account with any application. There will be no problem at the time of access.
Now if you install any android application in your mobile or tablet this is your own responsibility. Google is not responsible for your data security.
Important thing for gmail less secure apps turn off
One more important thing is that if you are using two-step verification in your google account then this option will not see you. Gmail less secure apps option available only for those people who are not using 2-step verification.
If you want to turn OFF gmail less secure apps option then you need to first stop two-step verification.Then you can turn off this option.
After doing this you are fully approve to use any type of application. To remove any app access. Go to your web browser and open your google account. Click on connected apps & sites and manage them.