Need suggestions on the best QR Code/bar code scanner app for smartphone

In my opinion QR Code Reader is going as one of the fastest QR code scanner available currently.
Users found it to be quite Fast and reliable with no unnecessary
ad breaks, looks good, and it is capable of catching even blurry QR codes which is quite rare.

To scan a code you need to just open the app, direct the camera towards the code, and things get done! You don't need to take any snap or even press a button. The Reader itself will recognize the code automatically that your camera is directed at.
While scanning a QR code, if the code consists a website URL, it will automatically take you to the site. And if the code is just a text, you'll get to see it immediately. For any or every other formats like contact info, phone numbers, , or email addresses it will prompt to take the required step.

Some Important Features you might be looking for:
• There is an option of viewing a history list containing all of your past scans
• You can choose to Synchronize your scan history through the web and also through all your devices that you are using.
• Scan the pictures of the QR codes directly from your camera roll
• There is also a switch to turn on the light of your device if you have to scan in low-light.

Not very sure whether that serves your purpose, but that is what I found after quite an extensive search.

Thanks Anwesha, but does it scan only QR codes or bar codes as well?
Update - It is the same app I have on my phone right now. I know it is the best in class, but after recent updates, it has gone quite unreliable as it does not scan QR codes sometimes.

Yes Timmappa, I searched for it again, and found that this QR BARCODE SCANNER Code Reader which can do the following things:
Scan QR Codes And Barcodes from
Mode Option
Camera, Image Files and Urls. You can also Create Your Own Qr Codes Encoding, Create Your Own "oldy" Barcodes (EAN8, Ean13, Code39, Code 128), Share your Qr Codes through email
text messages, social Networks (Facebook, Twitter, Flipboard, Google Plus). It has Wifi and Bluetooth with Auto-Archive Every Qr Code which can be Decoded through a very simple History List. You can also jump directly to the Web Addresses that has to be Decoded.
You can perform Continuous Scan, use its Flash Light.

What I guess that the Update that you have installed might not have installed properly or might be conflicting with some features of your system.

These two apps can do the work :

1. RedLaser Barcode and QR Scanner - https://play.google.com/store/apps/details?id=com.ebay.redlaser&hl=en

2. ScanLife Barcode & QR Reader - https://play.google.com/store/apps/details?id=com.ScanLife