How do I use Truecaller in my smartphone

 Truecaller is a crowd-sourced application developed by Swedish company True Software Scandinavia AB. When installed, it collects contact information from your mobile device and uploads it to their server. The app does the same with millions of other Truecaller users.
Features of True caller
    - Three apps in one
    - Enable SMS filtering

Customise the phone UI
    - Tweak settings
    - Change the theme
    - Scan numbers using the camera
    - call recording
    - Back Up Your Contacts and Call Lists+
    - Do Not Disturb Feature
    - Full Caller ID & Call Blocker info
    - SMS / Message Blocker
1) Three apps in one
    When you install the Truecaller app, you'll find shortcuts to dialers, messages, and contacts on your home screen.    this is part of true caller app.
2) Scan numbers using the camera
    The number scanner is a genius little feature. When you open the sidebar, you will see a little preview at the top. Tap on it, give it camera access access, and show any camera number toward the camera.
4) Full Caller ID & Call Blocker info
    The mobile number tracker has the number caller ID and caller name, photo, birthday, sms, social information etc.
5) SMS / Message Blocker
    Spam consumes storage space with block, no worries about spam messages. Block text messages by blocking SMS blocker and SMS.
3) call recording    
    Truecaller recently introduced callback recording for all Android users, and is the smoothed callback recording app I've used. If Truecaller is your Contacts application anyway, it will look seamless.
Follow steps to ebabled call recorder:
    1) Download Truecaller app and configure it.
    2) Then tap on the three horizontal bars from the top-left.
    3) Select the option 'Call recording'
    4) Now, tap on 'Start free trial' button in the next window.
    5) All all the necessary permissions when prompted.
    6) Now, it will show a message 'call recording enabled.
How to remove your name from Truecaller
    1) Open app.
    2) Tap the people icon in the upper left corner.
    3) Then click on setting.
    4) From the drop-down menu click on 'Privacy centre'.
    5) A new page will appear, here click on 'Deactivate' option.
    6) A pop up will appear 'By deactivating account you will delete your profile data. Do you wish to continue?'
    7) Select Yes
How to unlist your phone number from the true caller
    1) Visit the official website, truecaller.com
    2) Then go to Truecaller 'unlit phone number' page.
    3) Enter your phone number with the correct country code.
    4) Verify 'I'm not a robot'.
    5) If you wish tick one of the reasons for unlisting, or else you can also type your reasons for removal.
    6) After that enter the verification captcha and click on 'Unlist' option.

It can take up to 24 hours before your number gets removed.
Best alternatives of Truecaller
1.Whoscall
Whoscall is one of the best caller ID services out there and hence it is one of the best Truecaller alternatives that you can use on your Android and iOS devices. The app has been downloaded more than 65 million times and has a repository of over a billion numbers. One of the best features of this service is its offline database which allows users to identify calls even when they are not connected to the internet.
This is a feat which even Truecaller cannot perform. Apart from the ability to identify callers, other features of the app include the ability to block spam calls, blocking of specific numbers, unknown numbers search to track unknown numbers, and more. If you are looking for a Truecaller alternative, you should definitely try this out.
Install: Android, iOS(free with in-app purchases)
2.Showcaller
Showcaller is yet another Truecaller alternative that is easy to set up and use. The app is really small (4MB) and doesn’t eat up much of your phone’s resources. It is also battery friendly and doesn’t drain as much battery in the background as Truecaller does. The app identifies most of the unknown calls and shows detailed caller ID info on incoming calls, showing you the names and photos of the people who are calling. The service is incredibly good at identifying and blocking spam calls.
In my testing, the app blocked almost all the spam calls. I also love that the app brings a fast T9 dialer allowing me to quickly search through my contacts. Other features of the app include unknown number search, offline database, built-in call recorder, and more.
Install: Android, iOS(free with in-app purchases)
3.CallApp
CallApp is an all-purpose caller ID app which not only identifies unknown callers and blocks spam calls but also comes with the ability to record calls. The app allows for the recording of both incoming and outgoing calls and is a boon for users who want this feature. Of course, being a caller ID app, its main function is to identify unknown numbers, which thankfully, it does quite well. I have to say that spam call blocking here was not as good as with some of the other apps on this list.
However, it might just be that I was receiving more spam calls when I was testing this particular app. One thing that I don’t like about this app is its battery consumption. In my testing, the app consumed more battery and the drainage was equivalent to results I observed when using Truecaller. That being said, it still is a very good caller ID and call recording app and deserves a place on this list.
Install: Android
4.TrapCall
If you are an iPhone user, TrapCall is a worthy alternative for Truecaller. While the app is also available for Android users, the ratings on Play Store imply that their Android app is not as good. That said, ratings don’t always tell the whole story, so you can check it out.
TrapCall brings a ton of features that lets you block spam calls and identify callers, and more. First is the “No Caller ID” feature that uses TrapCall’s patented technology to let you know who is behind an anonymous blocked caller ID. This comes in handy when deciding whether to accept or reject a call. There’s also automatic spam blocking that blocks most of the robocalls. They keep an updated global list of spam callers so you always get the latest protection. The app also allows you to easily blacklist harassing and annoying callers. The callers hear a message that your phone has been disconnected so they are none the wiser. There’s also support for “Live Caller ID” just like Truecaller. Other features include the ability to record incoming calls, privacy lock for unidentified callers, and more. As you can see, TrapCall brings a lot of useful users and can easily replace Truecaller from your life. Note: TrapCall is only available in the US.
 Install: Android, iOS
5.Caller ID
As its name suggests, the app can identify calls and show you photos and names of unknown callers. The biggest feature of this app is its ability to sync with social media profiles. The app syncs with Facebook and other social media channels to identify your contact’s true photos to create a photo-based address book and dialer. That means you will receive much more information on unknown numbers using this app than either Truecaller or any other caller ID app on this list.
That said, the app has a smaller database than Truecaller which means it won’t work as consistently as the latter. I recommend that you use this app as a backup, as for contacts it has the data on, you can get better information. Other features of the app include the ability to block spam calls, availability checker, and more.