Snapchat is a simple app that lets you communicate with your friends using only pictures which they can see for only a few seconds before they disappear forever.
The way the app works is very simple: you take a picture, add a text caption if you want, select for how long you want the other person to be able to see it, and then send the picture.
TeamViewer is a remote access application that grants you access to other computer and work on it as if it were the one you are in front of.
The first thing you have to do is to install TeamViewer on oboth computers, the accessed and the user. From then on, you'll be able to control the other computer remotely.