Yes, both Scanlink and Mission Planner work in locations without internet access. However, the apps will not be able to download location maps and, in the case of Scanlink, mission components. Therefore, if you plan to capture in locations without internet, preload the required components while you do have internet access. To do so, open your preferred capture app and centre the map on the tower location, then zoom in as much as possible. The map tiles you need are now cached in the app memory and will be available when you are onsite. If you are using Scanlink, also tap on the mission you intend to fly.