The best way to run truecaller is to install this app called 'Island'. This creates a new profile called work profile for you. Use a new google id for this work

The best way to run truecaller is to install this app called 'Island'. This creates a new profile called work profile for you. Use a new google id for this work profile. Then install true caller inside island. I rarely use it but all I have to do is turn on the work profile, look up a number and then turn it back off. I keep all crap apps in the work profile since there is a shortcut in the android drawer to turn it off and on in 1 click. I also assume it saves a bit of battery since these apps can't drain it while work profile is off.