When possible, utilize a computer over a smartphone or tablet.

Computers are more durable for multi-hour long meetings, can remain plugged in, rely on Wi-Fi, and allow for easier sharing and review of documents over mobile devices. Additionally, unlike computers, smartphones are susceptible to frequent interruptions such as calls and texts by outside parties, which may interfere with the mediation experience. 

Of course, your smartphone or tablet may work fine, especially if you are not near a computer, or if the mediation will be relatively quick.