If you use the Chrome web browser instead of Firefox, Safari or Internet Explorer, you probably saw an on-screen notice for the Chrome web store. It has thousands of free apps. We did a little shopping (can’t beat the price) and here are three we liked.

Having a large number of browser extensions can slow down your web surfing. But apps only use your computer memory while you’re using them. We just installed the free Marvel Comics app, for instance, which puts an icon on the screen but doesn’t add itself to your browser. After installation, we clicked “Free” and got an “Avengers” comic book and could have gotten dozens of others, including X-Men, Wolverine and Captain America.

The other apps we installed were a calculator and “RemindMe,” which plays a little tune and delivers a pop-up note when it’s time to do something. The calculator is just a regular on-screen calculator. But it’s free and handy to have. (There are many free calculators you can install, including some that do scientific and interest rate calculations.)

If you have an Android phone, you probably use a web browser called “Browser.” But the Dolphin browser is better, and it’s just out in a new version for iPhone and iPad.

The Dolphin is like the web browsers you’re more familiar with Internet Explorer, Firefox, etc. but it lets you swipe a finger to reveal a sidebar with handy links to favorite websites and other menu items. Moving your finger in a pattern, such as a heart, will open your favorite website. You decide what the pattern should be.

Nine million people have downloaded Dolphin to an Android device. (We use it on our Vizio tablet.) Go to dolphin-browser.com for more info.

– Nearly two thirds of Americans now use more than one computer, smartphone or tablet on a weekly basis, according to a new survey by pollster Harris Interactive; fifteen percent said they use four or more. A little over ten percent said they usually want to browse the Internet while on a date, and seventeen percent said they need access on their honeymoon.

Chrome is our favorite web browser at least this month. Google came out with a new app for Chrome that lets you block any website from appearing in search results. Say you like news but hate what have come to be called “content farms” in the trade. These are sites that dish up news surrounded by lots of ads. Click to block those sites from ever coming up in your search results list again. Shoppers might want to block eBay, if they never shop there. Parents might want to block Facebook or more dangerous sites.

To get the blocker, install Google’s free “Personal Blocklist” from their web store at chrome.google.com/webstore. To use it, do a Google search as you normally would. Then look for the “block website” link under each result.

But it’s also because we’ve become used to it.  We can hold down the “CNTRL” key and tap the “h” key to see a history of where we’ve been on the web. We can hold down “CNTRL” and the “j” key to see everything we’ve downloaded.  If we hold down the “CNTRL,” “SHIFT” and tap “B” we can see all our Bookmarks.

There are a number of other web browsers, and you can roam among them at will:

– Flock, for example, is a social web browser.  It keeps you up-to-date with your Facebook and Twitter friends. You can use it to share web pages, photos, and video, update your status and make comments from anywhere on the web.

– Opera is mainly known for its speed. It’s very popular in Europe and on phones. It has an app called Opera Unite for sharing large files. Something about its look never appealed to us.

– Maxthon is light and won’t take up much of your computer resources. Similarly, K-Meleon is an extremely fast, customizable, lightweight web browser.

Some browsers, like iCab, (for Mac only) aren’t free. ICab costs $20 but claims to have features that Safari, the free Mac browser, doesn’t.  There’s a limited use free version, and the mobile version is $2. You can find still more browsers if you Google the search: “list of browsers.”

You can safely install as many browsers as you wish, and use each one as often as you wish. They do not interfere with each other.

There are lots of ways to browse the web anonymously. Internet Explorer 8 lets you do this for free.  Click “safety” in the upper right of the Explorer 8 screen and you will see the “InPrivate” label. This means your own computer won’t record sites you visit or what you do there. If you choose “InPrivate Filter” from the drop-down menu, websites won’t save records of your visits on their servers. You can do the same thing in Firefox with any of several free add-ons you can find ataddons.mozilla.org. “Better Privacy” has nearly three million downloads.

If you need more, there’s “Anti Tracks,” a $35 program from giantmatrix.com.  It gives you tools to shred specific files, eliminate duplicates, lock certain folders, wipe a hard disk clean, hide files in pictures or audio files, etc.

There are too many Opera features to go into here, but one of the neatest is Opera Unite.� This lets you share files, photos, music and videos without having to attach them in an email. You can even chat with people who are looking at your postings. You get a special link, and it can be password protected. This is great not just for your friends and colleagues but for yourself if you’re on the road and need to get at something you left behind. You must leave Opera Unite running for this to work.

When you install Opera, you get a panel on the left-hand side of the browser window with a series of icons. Some are pre-installed and there are hundreds more you can add. Clicking on Notes� opens up a note-taking area. �Click on �the fridge for reminders. There are icons for contacts,bookmarks,� and history,� showing where you’ve been on the web recently.

You can get the new Opera 10.5 as well as Opera Mini,� a super-fast browser for your cell phone, at opera.com. (A final note here: Sometimes a web site will appear slightly differently in different browsers. This is especially �true on cell phones. �That’s why it’s good to have more than one.)

The new Opera version 10.5  is lightning fast with fun features.

As we’ve said before, when it comes to web browsers, the more the merrier. We’ve tried them all: Firefox, Internet Explorer, Safari and Chrome and each has different strengths.

There are too many new Opera features to go into here,but one of the neatest things about Opera is “Opera Unite,” a way of sharing photos, music and videos on your computer without having to attach them in an email. You get a special link to share, which can be password protected.

When you install Opera, you get a left-hand panel on the side of the browser window with a series of icons. Some are pre-installed and there are  hundreds more you can add. Clicking on “Notes” opens up a note-taking area.  Click on  ”the fridge” for your reminders. There’s also an icon for “contacts,” “bookmarks,” and “history,” showing  where you’ve been on the web recently.

You can get Opera 10.5 from Opera.com. You can learn more about Opera Unite at unite.opera.com.

This is a landmark. It was just a couple of years ago that Internet Explorer dominated the world of browsing the Internet; it was used by more than 90 percent of people who went online. Of course that was mainly because it came packaged with Windows, so anyone who bought a computer automatically had it. But you can have as many Internet browsers as you want on your computer and gradually people began to move toward something better. Even Joy’s sister, who is totally baffled by computers, now uses Firefox for email and web browsing. So it’s still true, that if you make a better product, you will usually win out.

Many scripts are harmless, however. So if you’re on a site you trust and you get a warning from “NoScript,” you can temporarily allow the script or add that site to a list of trusted locations.

Another good add-on is PhishTankSiteChecker, which prevents Firefox users from being swept off to a malware site that looks like the one they thought they were going to. Instead it’s a phishing site, so naturally it’s called a “phish tank.”

There are hundreds of these add-ons and you can see all of them at addons.mozilla.org.  Bob likes Scrapbook, Screengrab and Cool Previews, which lets you view a web site before actually going there. Almost all these add-ons are free; a few ask for a small contribution to the author. As we’ve mentioned here before, you can have as many browsers as you want in Windows.

If you have the latest version of Firefox, you’ll see icons for all of your add-ons in a mini taskbar at the bottom or top of your Firefox screen. If you didn’t see your add-ons, go the “View” menu at the top of the screen and check “status bar.” To get the latest version, go to “Help” at the top of the Firefox display screen and choose “check for updates.”