The appeal of Genius Maps by Mireo over the default Google Maps on Android or Apple Maps on iOS, is its downloadable, locally stored maps for almost every populated region of the world. Map data is provided by Navteq, separated into manageable chunks such as USA Western or South East. Most interestingly, the map data is all to download. So you could theoretically install Genius and download maps for the entire world without spending a penny. There is, however, a catch.
Though the maps may be free, the Pro Guidance routing software that you'll need to actually get anywhere isn't. In order to unlock turn-by-turn navigation, automatic rerouting, speed alerts, lane assistance, and "POI Along the Route" functionalities, you'll need open you digital wallet and pull out up to $49.99 per continent. The North American license that I used during testing is valued at $39.99. This is a one-time purchase and a lifetime license, so you'll only need to pay that once. After installation, you'll have access to a seven-day trial period before you're asked to buy.
The Genius Maps app for Android weighs in at 33.12 MB and the USA West Map that I used during testing is a 307 MB additional download. The total installed size on my Google Nexus 5 came to 370 MB, the difference being filled with voice guidance and other data stored by the app. It was nice to not have to fill up the entire internal memory with maps, but you could probably get enough maps for a coast-to-coast U.S. road trip in about 1 GB.
Though the entire app can be operated offline and without a data connection, you'll need to connect to the web to take advantage of the optional traffic data and incident reporting. The traffic service also costs extra (between $12.99 and $29.99 depending on the continent you're licensing). The North American service that I tested is valued at $12.99. Again, this is a one-time purchase with a lifetime license to access the service.
The last decision that you'll have to make during setup is what voice to use for the spoken turn-by-turn directions. Mireo offers a selection of free TTS voices in a variety of languages, each weighing in at about 1-2 MB per voice and each a free download. There are a few celebrity voices available at additional cost, also additional size since they don't use TTS. For example, comedian Doug Benson was available (11 MB) for $4.99, but an error with my Google Play account prevented me from purchasing and trying this feature.
Good looking interface
It bears repeating that the appeal of Genius Maps is its downloadable, locally stored maps for almost every populated region of the world. The user retains access to these maps and the turn-by-turn routing software, even when the phone is outside of wireless coverage or offline in "Airplane Mode."
This guaranteed functionality is great for long road trips through spotty coverage zones, for users with extremely limited data plans or hard data caps, and drivers who like to stay off the grid. It's also useful for world travellers, who may find themselves in a foreign country with limited data connectivity and without access to cloud-based maps. The user can just download maps and pay for a license in whatever country they plan on visiting to have access to unlimited driving and walking directions.
Totally offline operation also makes this app a good candidate for increasing the usefulness and functionality of Wi-Fi-only devices, like the Nexus 7, when out and about.
I also enjoyed Genius Maps' great looking interface. The main map screen offers minimal distraction and packs a lot of information into small space along the bottom edge of the screen. The bulk of the screen real estate is devoted to the map, which animates smoothly and is rendered with crisp graphics. Automatic Day and a dark Night mode schemes keep the app visible whenever you're driving.
The Navteq map data is pretty accurate in my San Francisco Bay Area testing and the routes chosen by Mireo's software were logical and easy to follow.
Destination search needs work
Unfortunately, I found Genius Maps' destination and address search to be its Achilles' heel. For starters, the functionality is lacking and limited. Locally stored POIs can be out of date, since they're not refreshed from a live Web database. I know that the point is offline navigation, but I'd like to have access to some sort of online search (Google Local? Facebook Places? Foursquare? Bing?!) for the times that I actually do have a data connection.