DIY OS mapping / sat nav

[RDBx]

I don't know if this is best here or in the gadgets section, so here goes.

I've got an old galaxy phone and will shortly have a note 2 that'll be idle. I'm wondering if it's possible to root one of these devices and install some kind of OS 25k based mapping / sat nav system on there? Just want it to display my location on the map and perhaps allow some kind of route / navigation. Not interested in retaining is as a phone in any way, primarily for battery life.

I already have a Garmin 510 and it's telemetry is spot on for my needs and the turn by turn navigation is fine for road rides but hopeless off road.

Has anyone come across something like this?

[Oystercatcher]

Viewranger. Download the app and use free maps, e.g. Open Cycle/Steet map, or pay them some money and download OS 25k or 50k map tiles.

I've used it for walking for ages, now use it on the bike too. Records tracks with distance, height gained, Ave speed etc.

[shouldbworking]

Maverick app. All sorts of maps including various os scales, opencyclemap, caches them when you look at an area so if you look at it before a ride you'll still have them out in the back of beyond with no reception.

[C0ffin D0dger]

Google MMTracker, you won't find it on the play store. It will display the old format Memory Map OS mapping (.qct files), the maps can often be found on your favourite download site Worked quite well on my Galaxy S2 but a bit flaky on an S4, not sure why but it does work well enough to use.

[Trtj]

Download the app 'OsmAnd'. You can then create GPX route in strava, garmin, map my ride etc and then import it directly into 'OsmAnd'. Then enjoy turn by turn sat nav through your ear piece without the need for a data connection, just leave the gps turned on.