Android security issues make the news just about every day, from malicious apps appearing in the Google Play app store to mobile malware spreading via SMS. While Android is a flexible and easy-to-use mobile operating system available on a wide variety of great devices, the mobile threat landscape has now made it essential for users to install additional security options.
Keep in mind that the most basic security precautions, like password-protecting your device and setting it to auto-lock after a specified period of time, don't require an app – both of those features can be accessed within Settings > Location & Security. And most Android devices offer a variety of unlock options, including a numeric PIN, a password or a graphical pattern.
But don't stop there. From anti-virus apps (crucial at this point) to enhanced password protection, it's worth taking a look at several more advanced options. The vast number of security apps available for the platform makes it impossible to cover them all here, but what follows should give you a good sense of the options available when seeking further protection for your Android device and the data that resides on it.
Lookout Security & Antivirus (free) blocks malware, spyware and Trojans, with user-schedulable daily or weekly anti-virus scans as well as automatic scanning of new apps and files when they're downloaded. Additional features include the ability to locate a lost or stolen phone on a Google map and activate a loud alarm to help find the device, and the ability to back up and restore the user's contact list. Lookout Premium ($29.99/year or $2.99/month) adds phishing protection, privacy protection, remote lock and data wipe functionality, and the ability to back up and restore the user's photos and call history in addition to contacts. Lookout

Avast avast! Mobile Security (free) provides a wide range of functionality, including a Virus Scanner that enables on-demand scans of all apps installed on the device and SD card, along with scans of any newly installed apps upon initial execution. The Privacy Advisor displays the access rights and intents of installed apps, identifying any potential privacy risks. The Application Manager shows a list of running apps along with their size, CPU load, used memory, and number of threads and services, and enables the user to stop or uninstall any app as needed. The Web Shield scans every URL loaded on the device, and warns the user if a malware-infected site is being accessed. The SMS and Call Filter can be used to filter calls and/or messages from the user's contact lists. The Firewall, usable only on rooted phones, can disable an app's Internet access when on Wi-Fi, 3G, and roaming networks. Finally, Anti-Theft features include the ability to disguise the app with a custom name, to hide the app icon in the app tray, and more. If a device is lost or stolen, it can be remotely prompted to sound a siren, lock, display a custom message, be located on a map, be wiped remotely, and more.

AVG Antivirus Free scans all apps, settings, files, and media in real time; guards against phishing attacks; blocks access to malicious Web sites; kills tasks that slow down or freeze the device; and allows users to locate a lost or stolen phone via Google Maps, lock the device remotely, display a custom lock screen message, and make the phone ring even if it's on silent mode. AVG Antivirus Pro ($9.99) adds battery and storage optimization, along with the ability to secure apps from being accessed by others using your phone, and the ability to back up all apps to the user's SD card. AVG

NQ NQ Mobile Security (free) blocks viruses, malware, spyware and Trojans, and blocks access to phishing sites. Privacy protection monitors apps that access your private data without permission, and system optimization closes apps that run in the background without your knowledge. Traffic monitoring functionality ensures that you don't go over your plan's limits, and allows you to rank apps by data consumption. Contacts and messages can be backed up for free, and the app can also be used to locate a lost or stolen phone. NQ Mobile Security Premium ($19.99/year) adds automatic virus database updates, spyware alerts, online banking protection, and the ability to lock and wipe a lost or stolen phone, and to activate an alarm remotely.

TrustGo Antivirus & Mobile Security (free) enables on-demand or scheduled scans of your phone and SD card to find and remove viruses, malware, spyware and Trojans. The app's Secured App Finder Engine helps users find and download apps that are known to be safe. The app can also provide alerts when users browse to malicious Web sites, and can monitor and manage the phone's data usage, battery consumption and memory usage. A privacy dashboard displays all permissions used by installed apps. Device data can be backed up in the cloud, and a lost or stolen phone can be located, locked and/or wiped, and an alarm can be set off remotely. TrustGo

McAfee McAfee Mobile Security ($29.99/year) offers anti-virus scanning, blocks access to malicious Web sites, backs up and restores personal data as needed, checks applications against McAfee's TrustedSource URL reputation database to make sure the apps aren't associated with risky Web sites, enables filtering of unwanted calls and texts, blocks other users from uninstalling the app, and provides the ability to locate a lost device, remotely lock all data on the device, and remotely wipe all data if needed.

Norton Mobile Security ($19.99/year) scans all apps and app updates for threats, collects information provided by Norton users to identify threats more quickly, blocks phishing sites, allows users to block unwanted calls and texts – and, for a lost or stolen device, allows the device's owner to locate the device, lock it remotely, wipe all data remotely, display a customizable message on the device, take a photo remotely, and set off a loud siren as needed. Norton

Webroot Webroot SecureAnywhere Mobile (free) scans all apps and files for viruses, spyware and Trojans; blocks access to phishing Web sites; blocks unwanted calls and texts; and allows users to locate a lost or stolen device on a map, remotely lock the device, and sound an alarm as needed. Webroot SecureAnywhere Mobile Premier ($19.99/year) adds the ability to lock the device automatically if the SIM card is removed; remotely wipe a lost or stolen device; monitor battery status and power usage; view apps that are accessing the network; and identify apps that can access your messages, cost you money, access sensitive data, track your location, and/or drain your battery.

Kaspersky Mobile Security ($19.95/year) offers both on-demand and scheduled virus scanning; the ability to locate a lost or stolen phone, and to lock and wipe a stolen phone even if the SIM card has been replaced; blocking of unwanted calls and texts from both specified and unknown numbers; and a privacy mode (activated manually, automatically, or remotely) that hides specific contacts, calls, and texts. Kaspersky

Trend Micro Trend Micro Mobile Security Personal Edition ($29.95/year) scans all files and apps for malware; blocks unwanted calls and texts; blocks phishing Web sites; enables parental controls to block inappropriate Web sites, calls and texts; and locates a lost or stolen device, sounds an alarm, and locks and/or wipes the device. The app can also automatically lock the device if the SIM card is removed.

Bitdefender Mobile Security & Antivirus (free) scans apps as they're installed (or on demand) to check for malware; provides a clear view of all app permissions, noting those that can access the Internet, view sensitive data, and/or incur charges; and enables the user to locate a lost or stolen device. A Premium version ($9.95/year) adds the ability to block access to phishing Web sites, and to lock and/or wipe a lost or stolen phone, sound an alarm on it remotely, and/or send a customized message to the device. Bitdefender

ESET ESET Mobile Security ($9.99/year) scans downloaded and accessed applications and files for malware, blocks unwanted calls and texts, and allows the user to locate and remotely lock and/or wipe a lost or stolen phone. If an unauthorized SIM card is inserted in the device, the app can automatically send a text message to an alternate phone number. A built-in task manager also monitors the phone's battery life, free disk space, running processes, Bluetooth connectivity and device visibility – and all settings can be password-protected to prevent unauthorized modification or uninstallation.

Sophos Mobile Security (free) scans every app you install for malware, and offers an on-demand scan of all apps, include those on the device's SD card. The app's Privacy Advisor enables the user to filter installed apps according to their risk potential, including their ability to incur charges, to harm privacy, to access the Internet, etc. The app also provides users with the ability to lock and locate a lost or stolen device. Sophos

GadgetTrak If you're mostly concerned about tracking a lost or stolen device (rather than scanning for malware), GadgetTrak Mobile Security ($19.95/year) uses a combination of GPS, Wi-Fi positioning and cell tower triangulation to track a device's exact location. All photos and contacts on the device can be encrypted and backed up securely. In case of theft, a piercing alarm can be activated remotely even if the device is in silent mode, and all personal data can be remotely wiped from the device and the SD card. The software is designed to be tamper-proof, and alerts the user to any unauthorized SIM change or assignment of a new number to the device.

Moving on to password management, LastPass Password Manager Premium ($1/month) combines an Android app with a PC-based browser extension. A master password provides access to a cloud-based password vault, and the app and extension can fill in site passwords for you automatically, both on your PCyou're your Android smartphone. The Android app includes a built-in browser, a secure password generator, and the ability to add, update and delete notes and Web sites to and from your saved data. LastPass

SplashID SplashID Safe for Android ($9.99) stores passwords, credit card numbers, registration codes, PINs and other vital information, guarded with dual 256-bit AES and 256-bit Blowfish encryption. Optional desktop software ($19.95) can be used to sync the data wirelessly with a PC.

1Password Reader for Android (free) provides mobile access to user names, passwords, credit card numbers and other data stored via the desktop version of the software ($49.99), using Dropbox to sync between the two. The Android app keeps data protected either with a password or a four-digit unlock code. You can't modify the data from your Android device, though – you can only do so using the desktop software. 1Password Reader

mSecure The mSecure Password Manager for Android ($9.99) protects passwords and other data using 256-bit Blowfish encryption, and stores the data using any of 17 different personal information templates, along with the ability to create your own custom templates as needed. The app syncs with the company's desktop software ($19.99) either via Dropbox or over Wi-Fi.

Seal App Locker ($2.54) can be used to individually protect any app, from Google Mail to Angry Birds, with a complex password, a numerical password, or a pattern. Protected apps can be grouped into profiles to be locked and unlocked as a unit, and protection of each app can be enabled or disabled easily from the Seal interface with the tap of a radio button. Seal App Locker

App Protector Pro App Protector Pro ($1.50) locks individual apps with either a password or a pattern. Both automatic and manual locking modes are available, and apps to be protected can be chosen quickly via checkboxes on a list of all apps on the phone. A widget is available to enable quick locking and unlocking, and a password recovery feature is built into the app.

Jeff Goldman is a freelance journalist based in Los Angeles. He can be reached at jeff@jeffgoldman.com.