It was just about a year ago that Eastern National, a non-proft that produces interpretive and educational materials for national parks, introduced its first cellphone app, for iPhones. Well, 'Droid users, your day is here. The organization just released a similar app for your phones.

The app, logically called Passport: Your National Parks, lets you quickly identify where in the National Park System you can collect passport postmarks that reflect which parks you've visited and on which dates. Now, you won't collect the postmarks electronically on your phone, but rather stamp them in your Passport to Your National Parks handbook, which also contains space for you to paste in commemorative regional stamps to the parks.

Beyond that, the app is kind of a phone book to the park system. It brings to your smartphone every unit of the National Park System, and allows you to mark parks you would like to visit as well as those you have visited.

You can locate parks by name, state or “nearby” using GPS technology, if your phone is capable of that and you've enabled it. There also is a digital scrapbook for each park that allows you to log a journal entry, record the date of your visit, and import photos with descriptions. You can find park addresses, phone numbers, National Park Service websites, plus entrance fee and junior ranger program information.

Hot links in the app connect you with a park's nps.gov website and information on entrance fees, Junior Ranger programs, even events. However, sometimes this information is only as good as what the Park Service lists. For instance, in February the events page on Acadia National Park's website was listing programs for last September.

Additionally, this app should not be confused with a guidebook to the parks. For instance, you won't find hiking information directly on the app, but rather be directed to the park's official website to locate that information.

Finally, since this is a 'Droid app, and there are many different phone manufacturers that use the Android architecture, there might be variations in how you navigate the app.

For instance, if you want to add a "Park to Visit" or "Parks Visited" to your app, you need to find the park by name. That will take you to the main "Park Details" page that lists the park information and contains hotlinks to additional information. On some phones, there's a small plus sign (+) in the upper righthand corner of the "Park Details" bar. Click on that, and it'll open a new page on which you can jot down notes. Once you save that information, you can proceed to another page that lets you upload photos.

However, some phones fail to show that plus sign. For instance, on Casio phones (at least some models) sold by Verizon the plus sign does not appear in the Park Details bar. Rather, on the base of your phone there's an index bar you click to bring up options. Tap this function when you're on the park page of your choice and you'll see options to mark this park as a "favorite" or to add visit information or to mark the park as one you want to visit.

To download this free app, you can find it in the Google Play store at this address.