Kaspersky Mobile Antivirus 
Kaspersky Mobile Antivirus is one of the best apps for Android security that you should have on your device. It keeps you secure from malware threats via its brilliant virus detection software. It can easily search through the browser history, microSD card and also the internal storage space.
Notable Features 
•    Virus Cleaner and automatic malware blocking;
•    Scans on-demand and in real-time for viruses, spyware, ransomware, and trojans;
•    Protects personal information from thieves by wiping it from your device
•    Add secret code to access your private messages, photos & more
•    Keeps your financial information secure when you shop & bank online.

CamScanner
CamScanner is another one of the must have Android apps of all time for your device. This app uses your phone’s camera to scan documents. It has smart cropping and auto enhancing features for texts and the graphics so that they shall look clear and sharp. 
Notable Features
•    Smart-enhance multi-page documents scan with several enhanced modes
•    Auto-crop scanned photos and save results to the system in PDF/JPEG format
•    Add notes and tags to any document for easy search
•    Fax scans via a network, sending PDF files via email
•    Upload files to cloud storage, and print files wirelessly with Google Cloud Print.

Google Translate
Google Translate has become a best friend to all the android users who are frequent travelers in foreign countries. Google Translator comes among the top Android apps of all time, as it has the capability to translate at least 103 languages by typing and offline around 59 languages.

Notable Features
•    Store language offline
•    Translate the highlighted text in any doc
•    Convert signboards written in another language into your own language
•    Integrated into the Chrome, Google app, and the Gboard app
•    Custom phrasebook to save important translations for quick access later.

Source: mobileappdaily.com