TeamViewer is an excellent screen-sharing and file-transfer app that can be used to facilitate business collaborations as well as helping distraught relatives diagnose and cure computer problems. Along with being free for noncorporate use, it gives users precisely the tools they need to share screens securely, send files with a minimum of hassle, control access rights, and even flip which user has control.

The options available while you're in control work smoothly. You can maximize the pane that the other computer's screen is visible in, as well as utilize several smart options from a drop-down toolbar in the center of the window. A big X lets you close the connection, while the Actions button lets you switch whose in control, disable remote input, and reboot remotely. The View menu hides options to adjust the screen resolution, the optimization toward speed or quality, and control multiple-monitor displays.

When you log in, you're given an access code and a password. Sharing those allows your computer to be controlled by the level you set it to: remote support, presentation, file transfer, or VPN. The TeamViewer servers remember which computers you've connected to, so reconnecting to previously shared computers happens faster. TeamViewer also has a Web-based version, for remote connecting to home from public computer. Even the installation process is impressive. Users can toggle admin rights, can opt out of running at startup, and can opt into installing the TeamViewer VPN driver for more secure screensharing. Overall, TeamViewer makes screensharing and file-sharing as fluid and unobtrusive as it should be.