Hey guys, I have an iPhone 4 sitting around collecting dust and I'm wondering about converting it to a Garmin style GPS unit. But here's the catch: I won't have any cellular service or data plan, only the build in GPS chip. I know people use their Google maps feature on the iPhone, but I won't have the ability to do that while riding since it's not an active cell phone with a data plan. Is there a specific app that allows you to pre-download all the maps you'll need for your route? Has anyone done something like this before? I am able to connect to WiFi to download maps, apps, etc.

All tips and ideas welcome.

On my iphone 5 I have both CoPilot and Offline Navigator. Both work without cell service or wifi. I'm guessing both were free, as I'm too cheap to pay for apps.

I'm not sure if they're available on the 4, but it's worth checking. Let us know how it works... Maybe I'll do the same with my old 4.

I unlocked my old iPhone4 and when I travel out of the U.S., I use it with a local sim as a local iPhone. It also serves as a backup for all the navigation on my newer iPhone. (Yes, I take 2 phones when I tour out of the U.S.)

This works, I've used it for gps nav:

OsmAnd - Offline Mobile Maps and Navigation

You may want to consider an inexpensive tablet with good battery and gps, as these make a better gps nav device than many phones. The big screen is easier to read, and the big battery lasts longer, especially if you turn it off during long idle periods between distant waypoints.

There are 2-3 other apps I tried which allow pre-downloaded maps. However, they either are not free, downland huge maps (whole USA vs individual states), and/or do not permit you to locate large map files on sd memory card, thus using-up all your device's memory.

I've heard of a Nokia GPS app that is supposed to be pretty good. I haven't used it, though, so I can't speak on it personally. It's something to look into, though.

Assuming you ride without a activated phone with GPS, if it works, which it sounds like it does, using an old deactivated phone as a GPS is a great idea.

Why not just save the Google maps you need on your phone. You can then access them offline.

I use tomtom on my iPhone. It has offline maps and thousands of POIs, plots great bicycle routes, calls out turn by turn instructions that actually make sense compared to the gibberish some programs do. The default display while navigating is a big red arrow that gets bigger as you approach a turn. That's much more usable at a glance than looking at a map and finding where you are and mentally projecting etc.

You can search the POI database and find grocery stores, motels, etc and navigate to those places and get their phone numbers.

ALL of the above offline. And if you DO have a network connection (like you're stopped at a WIFI) it will also search the Internet and you can save locations as a Favorite and then use it as a waypoint offline.

How to use the iPhone 4 as a GPS mapping device for backpacking

Nokia has recently put their HERE maps app back in the app store. It allows you to download and save offline all their maps for wherever you are going. I use it like a handheld unit and it works great though a bit slow.

Locus app ...