I would like to do a mobile native app (Android & iOS) with OpenStreetMap. I need to work with maps offline for trekking.
I read about OSMDroid, MapsForge for Android, but I need to do in iOS too. Could you recommend me some libraries, tips etc for these mobile OS?
Thank you
The OSM "stackexchange like" help might be a better place for this question.
See for example: https://help.openstreetmap.org/questions/8066/ios-android-sdk
Check also the OSM wiki: https://wiki.openstreetmap.org/wiki/Frameworks for possible alleys to explore.
If you are ok with a commercial library check out skobbler's OSM SDK - they offer offline maps and a free tier plan that might be large enough for your needs. (minus the marketing talk, the SDKs can be downloaded here)
If you are an company/enterprise then also have a look at cloudmade (as far as I know they changed their policy and supported only enterprise plans).
