Android: ESET Mobile Security is a full suite of security and privacy tools rolled into one app. Full-phone antivirus and malware scanning, call/SMS/MMS blacklisting, and a host of anti-theft features are all accessible from the main screen. As if that weren't enough, the app also has built-in system monitoring functions to show you every running process along with its resource usage. The app's in beta at the moment, but it runs as smooth as it looks—and it's free.
ESET's antivirus scanning is one of the most trusted in the industry, and the mobile scanner hasn't been gimped like you'd expect in a mobile app, either. Full-system scans are available at any time, while on-access scanning runs in the background to check files as they are downloaded. Basic scanning is enabled by default, but available options include SD card scanning for every file that appears there, as well as advanced heuristics (which would help catch undocumented threats, but use slightly more processing power when in use). Settings also include particular file extensions to check, along with whether or not to check archive packages like .zip files. Detailed logs and a standard quarantine are used for all scans.
Antispam features apply to phone calls, text messages (SMS), and multimedia messages (MMS). They allow for specific blacklisting of phone numbers—with options for both incoming and outgoing blocks. Users can also opt to simply block all unknown numbers—or more interestingly, all known numbers. If either blanket rule is in effect, individual numbers can be whitelisted with rules of their own.
Antivirus and antispam are both extremely important features, and they're done very well in ESET Mobile Security, but the section of the app that's probably the most interesting to Android users has got to be its anti-theft capabilities. The first time you load the app, it displays a large alert to let you know that it hasn't been secured yet. After following easy and well-explained cues, a user should have the app added as a device administrator, defined the currently loaded SIM card as "trusted," defined contact numbers to which alerts should be sent if the phone gets stolen, set a master password for the app, and finally, set the app to protect itself against uninstall attempts.
Afterwards, should the phone be lost or stolen, the app can be contacted via SMS messages and commanded to give GPS coordinates, lock the screen with a password, or even to begin wiping all data from the phone (including the SD card). If an untrusted SIM card is ever put in the phone, the app will automatically send out alert texts to the numbers set as alert contacts, with a pre-defined message that the user can set.
Then there's the Security Audit, which checks everything and presents a checklist to let the user know how locked down the phone is. It's also got a full-fledged task manager that displays currently running processes, services, and tasks on the system, along with the option to kill non-system apps.
Last but not least, the app's built-in help documents are outstanding. They're written simply and to the point, with a separate help button in every section of the app. Along with the app's well-defined interface, they make the entire thing a pleasure to use, and that's saying a lot for a security app.
ESET Mobile Security [Android Market]