Ecommerce merchants frequently find themselves selling products in venues other than their web stores. Be it in-store trunk shows, pop-up shops, trade shows, boutiques, local fairs or even coffee shops, ecommerce merchants are there setting up booths and selling merchandise.

In the past, merchants had to run cash-only shops or process credit cards on a laptop, but extra outlets and a reliable Internet connection can be rare at these events. Now, merchants can process credit card transactions on their mobile devices with a host of mobile apps and dongles. (A "dongle" is hardware that attaches to a mobile device for a secure connection.)

I looked at the top twenty-five credit card processing apps with the (a) highest user ratings, (b) good reviews and (c) the most downloads for each of the top three mobile devices: Apple’s iPhone and iPad, phones running Google’s Android operating system and Research in Motion’s BlackBerry. I then handpicked from that group of 25 the most highly-rated and useful for each device.

Download these apps and start selling merchandise anywhere you can get a cell phone reception.

iPhone and iPad

1. Square. This handy app can be used with or without the proprietary Square dongle (it plugs directly into your iPhone or iPad headphone jack), so merchants can swipe or type-in card account information. Receipts are sent to the customer automatically via email. Square does not require a contract, and a merchant account is not required for use. It comes with some helpful tools to track sales, payment locations, tax, and top-purchasing customers. Square charges $.15 plus 2.75 percent for a swiped card and $.15 plus 3.5 percent for typed-in account information. App cost: Free.

   

2. iPay POS. One of the most flexible credit card processor apps, iPay POS is a good option for merchants that already have a merchant account — iPay POS is compatible with dozens of the most widely-used payment gateways. You can also set up a gateway with iPay POS for $7.50 per month. For a small merchant that may not attend many events, iPay POS comes with 10 free transactions and additional sets of 10, each for $.99. Or for a merchant with a larger budget, $29.99 will allow for unlimited transactions. It has limited compatibility with dongles, but it is compatible with the iMag credit card swiper and portable receipt printers like the RedFin P25-M. App cost: Free.

3. Credit Card Terminal. One of the most widely-used credit card processing apps, Credit Card Terminal can process all major credit cards, handle full and partial refunds on returns, allows for digital signatures to be captured on-screen and PDF receipts can be emailed directly from the app. It is compatible with an optional Innerfence card reader dongle. Authorize.Net processing rates of $.25 per month plus an additional 1.74 – 3.79 percent rate depending on transaction type, also apply. Credit Card Terminal is only for use with Authorize.Net accounts. App cost: $.99.

4. Swipe It. Use the app by itself to key in credit card account information or in conjunction with the Swipe It Reader for card swiping on your iPhone, where you can capture a customer’s signature right on your phone and email receipts automatically at the end of sale. Merchants must set up an account with Swipe It's proprietary EPay gateway, which costs $15 (a one-time set up fee), then $20 per month and $.15 per transaction. App cost: Free.

BlackBerry

1. BlackCharge. Limited in payment gateway options, BlackCharge is only compatible with Authorize.Net, NMI and PayPal Payflow Pro. If you don’t have a merchant account, you can set one up through NoblePay. The app costs $4.99 and BlackCharge does not add additional fees or take a percentage for transactions, but the standard transaction rates for the compatible merchant accounts still apply. App cost: $4.99.

2. MerchantWARE Mobile. Process credit cards on the BlackBerry Storm, Curve, Pearl and Bold with this free app and email your customer a receipt at the end of the transaction. Although the MerchantWARE Mobile app is limited to use to a Merchant Warehouse — makers of MerchantWARE — merchant account, there are no additional gateway transaction fees or percentages, just the monthly cost of the merchant account, which varies depending on merchant needs. The app is also compatible with MagneSafe BT90 wireless Bluetooth credit card reader. App cost: Free.

   

3. vTerminal. Accept credit cards with this very simple app, which is also known as ChargeBerry. It doesn’t offer a lot of additional tools, but it allows the entering of numbers from major credit cards without having to use a swiper dongle. It has limited payment gateway compatibility, as it only works with Authorize.Net or PayPal Payflow Pro. There are no additional fees after the $9.99 download purchase, but standard gateway fees apply. App cost: $9.99.