Multiport chargers are very useful during travel. A USB wall charger provides the converted current through one or more standard USB ports. They transfer only power, not data. They provide fexibility, unlike a device-specific power adapter. With a multiport USB wall charger, you can easily connect your device to the charger using cables with a USB-B plug at one end and, usually, either a Lightning-connector (for iOS devices) or Micro-USB (for other gear) plug at the other. (Some devices instead use Mini-USB or a proprietary plug.) 

The best multiport USB wall charger: Anker 36W 4-Port USB Wall Charger (Affordable, fast, small size)

The second best multiport USB wall charger: Anker PowerPort 4 (more powerful, has folding prongs that are useful for travel, mor eprice)

The best powerful multiport USB wall charger: Anker 60W Charger 

The best multiport USB wall charger for travel: iClever Dual USB Travel Wall Charger (almost same size as Apple iPad charger, but twice the ports and twice the power at half the price)

The best multiport USB wall charger with a good docking station: Skiva StandCharger 7-Port USB Charging Station (useful for families)