Discussion: iphone app for mapping?

I'm trying to find an app to use on my iphone to help with mapping and was told someone on this forum might be able to help. I have a Garmin GPS (that can't show maps) that I will use to collect the main reference data.

The procedure I'm thinking of is:

1) Use garmin to get a track through the area to be mapped.
2) Use gps track to georeference government aerial map/image.
3) Draw O-map in OCAD over aerial image.
4) Load OCAD map into iphone and head out to do field work. Looking at map image on iphone as I walk around note features that need to be added, removed or edited. Mark a waypoint in both devices and make a note about edit to be made at that waypoint.
5) After fieldwork import gps track from both devices into OCAD. Where waypoints from the two devices disagree use garmin waypoint. Make edits.

Can anyone advise if there is an app that is suited to this task? Also, any thoughts on doing it this way? The main benefit I see is that it mightn't be necessary to carry a paper map - although maybe an iphone screen is too small to be practical? Also, if the iphone is accurate enough it might reveal inaccuracies or problems in the field, that would otherwise only be seen back at home once the track is uploaded to the computer. I have read that the iphone gps is quite accurate and problems are often with apps so don't really want to dive into this until I've researched the options.

You are looking for Ghettocad+ipad.

I've worked like this for quite a while, but using a Garmin Montana as the map display. On this and other recent Garmin models you can load a raster image exported from OCAD, using a tiled format which is optimized for this use.

I use my Garmin watch to mark details using the split time button, this is much faster than any of the regular waypoint options.

I have also used a map image loaded to my Android phone, but so far not for mapping purposes, just as a replacement for a paper map.

For Android there is an app called Custom Maps to help with field checking. The orienteering map is displayed with an arrow pointing to your current location. Updates are done on a paper map. Not overly high tech, but useful.

@haywoodkb: Thanks, Custom Maps is in fact the Android app I used. :-)

Thanks for your replies. I got a bit side-tracked from this project but am back at it now.

I've now got access to an android tablet I can use as well that gets GLONASS satellites whilst my garmin and iphone only get GPS satellites. So, I wanted to do a walk with the garmin and tablet to see how the tracks compare. I spent ages looking for an app for the tablet that would just record a simple GPS track like the garmin but have had no luck so far. I've installed a number of likely apps to find that one had no ability to select a datum, another required me to select a datum but the only local datums available were superseded many years ago, and another that appeared to work well until I went to transfer the GPX track to my computer and found I needed a key from the developer which wasn't provided.

I'm now looking at a garmin app called Garmin Fit but will try to get a little more info on it (not entirely sure yet you can download the GPX file). Although, I've noticed the GPS really chews through the tablet battery so also thinking it might not really be worth pursuing. I'm sure the Garmin GPS will be sufficient for the job but was interested in making a comparison.

I've visited the Custom Maps website and it's definitely something I'd like to try once I'm up to the next field work step. It's a pity it doesn't allow for edits on the device but still sounds useful.

Ghettocad seems a little mysterious - I can't find any tutorials or reviews and the help file seems a bit limited. I'm trying to download it but having a little trouble with itunes right now. Should be able to sort that out soon though and am keen to try out Ghettocad.

It turns out I can't put Ghettocad on my phone as itunes refuses to transfer it during a sync. It appears it can't be downloaded on the phone directly from the website and isn't available from the App Store. Does anyone happen to know a workaround?

You can't install Ghettocad without the author first adding your iPad's UDID (unique device id) to the list of devices that can use it.

Thanks Cristina - didn't realise it was invite only.