Do you hate to pay extra for the 3G / LTE version of your tablet / ipad / chromebook? But you still want to be online? Or do you travel with many WIFI devices and need 3G/4G internet connection?
Then consider to buy a "MIFI".
I used recently a affordable 3G / WIFI modem (see Amazon link below). It is battery powered for 4 hours and easy to use (just switch it on or off).
It is very easy to use, just insert the SIM (if the SIM is PIN-locked, use the integrated web-server to enter the PIN) then just switch it on and you have access over WIFI to the internet almost everywhere. The small box can be kept in your luggage or case. It just needs to be in the near of the wifi range. The existence of this devices in not well known, therefore I post it here.
For more devices and LTE versions, please go to more devices here at Amazon.