Mac: When you're tethering your Mac to your phone, you usually want to make sure you're using the least amount of data as possible. TripMode is an app that allows you to quickly and easily block specific apps the second you connect to a hotspot.
When you connect to a hotspot, TripMode automatically starts restricting access to the internet with any apps you have open. You can customise which ones get access and which don't. You can also monitor how much data they use, which is handy if you've got a data cap on your hotspot. For example, you can make sure your timed CrashPlan sync doesn't happen when you're on a hotspot, or restrict Dropbox until you're back on a normal Wi-Fi connection. You can also restrict apps manually, so it's useful if you're on public Wi-Fi or just trying to conserve a little battery life as well. There's a free seven-day trial of the app available on the developer's site if you'd like to check it out for purchasing.