How to remove GSearch app?

As you say in your question that you are not able to uninstall GSearch app from your device. And after uninstalling it appears again in your device. You can try to

uninstall all apps which are recently downloaded. If still you are facing the problem you can go for free anti-virus scan with Avast Free Mobile Security. As there are

many free security software available you can choose if you have one.

How to perform scan with Avast Free Mobile Security

1.First of all download AFMS(Avast Free Mobile Security) from link given below.
http://goo.gl/d0gi5E
2.You can also search this Anti virus in Play-store and download it. It is free and 7.47 MB in size. After performing all common steps you will be able to download

AFMS on your device.
3. After the installation completed AFMS automatically update its virus definition database.
4. Now It will start scanning your device for all possible malware and threats.
5. As the scan completes you will see all the threats and malware on your device screen.
6. You can delete it.
7. After that you can perform scan again manually and you will see the screen which says "No problem detected".

That's it now you will no more see Gsearch App on your device.

Note: Before downloading any app please know about it developers.

You will not be able to uninstall the GSearch app so easily. Even if you remove the app using any of the methods above, it will come back again. I would suggest following steps though it is not guaranteed -
1. Check if you have any other such app named GFirewall and Play Store. This Play store I am mentioning is NOT THE OFFICIAL STORE. If yes, try uninstalling them.
2. If you not able to uninstalling the apps, use any of your favourite Anti virus apps and quarantine all these three apps. That way, you may be able to solve the issue.