Four free, open-source Android apps work with no cell service, covering maps, sensors, first aid and survival tips. Set them up before the trip.
A How-To Geek writer who has recently taken up camping and hiking says four free Android apps now go with him wherever there is no cell service. All four are open source, meaning their code is public, and all work offline. They cover navigation, emergency medical help and survival basics.
Trail Sense uses the phone's built-in sensors and GPS to keep a hiker on track. It has no base map, but users can import maps or overlay a photo of a paper map. It drops pins and leaves "breadcrumbs" so you can backtrack. It also tracks sun and moon times, golden hour and local weather, and includes a flashlight, ruler and packing list planner. Its data stays on the device.
Organic Maps fills the gap. It shows roads, paths, settlements and points of interest, lets you search offline and can plan hiking routes. The writer pairs it with Trail Sense and finds it more useful than Google Maps most of the time.
One caution applies. Organic Maps relies on crowdsourced OpenStreetMap data. That is generally thorough, but trails, water sources and other features can be more or less complete depending on where you are.
PlainRescue is a free offline app that gives calm, step-by-step guidance for life-threatening emergencies. It has a searchable list of common emergencies and can be used one-handed. Each entry offers text, diagrams and a voice-guided option. A Learn tab teaches you before anything happens. Treatments link to sources such as the American Red Cross, the World Health Organization and the NHS.
The fourth app is a survival guide based mainly on the public-domain U.S. Army Survival Field Manual. It covers planning, basic medicine, shelter, water, fire and food, including traps and fishing devices. It also addresses the psychology of being stranded, plus navigation and harsh settings such as deserts. It works offline and its code is on GitHub.
It is not on the Play Store. The writer says the easiest way to install it is through F-Droid, a free, open-source app store. The article text provided cuts off before naming the app or finishing that explanation.
Install these apps and download your maps at home, because none of them can fetch anything once your signal is gone.
A 2024 review found phone radiation likely does not raise brain tumor risk. Trapped heat from a charging phone under a pillow is the bigger worry.
Read more: Sleeping with your phone under the pillow is a fire risk, not a cancer riskA writer removed popular apps from her Android phone after checking her screen time, and says she now spends less time and money on them.
Read more: A writer deleted 8 phone apps, and her screen time habits changedMany smart glasses have a camera that can record video, so you may be filmed without knowing. Price and eye strain are other things to weigh before buying.
Read more: Smart glasses can record you without you knowing
