Here are the corrections:

1. In the future, we'll be wearing a tiny device to catch our thoughts and send them to other people. (change "it" to "them")
2. Voice messages are more convenient than text messages because you don't have to type. (change "is" to "are")
3. People working in the technology areas have started researching for an integrated device. (change "start" to "started")
4. The application of augmented reality allows us to see a person's information without talking. (change "informations" to "information")
5. Cell phones are so important that some people become worried if they forget to bring their phones. (change "such" to "so")
6. Don't worry if you have some difficulty communicating with foreigners. (remove "to")
7. Because of the language barrier, they decided to use body language to communicate. (add "to" before "using")
8. It is impossible to count all the stars in the Milky Way. (change "on" to "in")
9. Where will people be living in 100 years' time? (remove "within")
10. One of my friends enjoys skiing at the weekends. (change "mine" to "my")
11. I don't have any iPods. This iPod is hers. (change "her" to "hers")
12. We need a high-speed Internet connection to have a video conference. (change "high-speedy" to "high-speed" and remove "make")
13. People spend a lot of time sitting in front of the computer every day. (add "of" after "front" and change "the" to "a")