It's easy to forget about your phone's dependency on modern infrastructure when you have free public WiFi and consistent access to electrical outlets. But for all their ubiquity in first-world urban spaces, smartphones become a lot more temperamental once they're out in the wilderness. To keep using your device's offline abilities when you go off the grid, the Universal Waterproof Solar Charger can come through in a pinch.
This portable battery pack will deliver a full recharge to your phone using nothing but sunlight. It has a second 2.1-amp port specifically for tablets and other more power-hungry devices, and includes handy adapters for iOS and Android compatibility. It's also built like a tank; this charger is fully sealed from water and dust, and is shock-proof to protect from unexpected drops. And to keep it off the ground entirely, it features a handy loop that comes with a carabiner to attach to it your gear.