The HTC Butterfly S has the usual quad-band GSM, plus several versions (for different regions or carriers) of 3G HSPA+ and region-dependent 4G LTE support.
The local wireless connectivity has Wi-Fi a/b/g/n/ac and DLNA support (both client and server, for images, videos and music) and stereo Bluetooth 4.0.
HTC has conveniently designed a special options screen, when you connect the Butterfly S to a PC. The long list of options includes Portable Wi-Fi hotspot, settings, USB and Bluetooth tethering (the phone becomes a modem).
HTC's Portable Hotspot can support up to 8 devices, you can use WEP, WPA or WPA2 encrypt the hotspot and enable only "allowed users" to connect or leave it open for all (unsecure, but the quickest setup).
The app can be set to power off automatically after 5 or 10 minutes of inactivity, saving your battery in case you forget to switch it off when you are done.
NFC connectivity with Android Beam is enabled too. We found it to work hassle-ree with webpages and heavier items like photos.
The HTC One comes with an MHL port, so if you plug a MHL dongle in, you can output HD video over a standard HDMI connection. The phone's UI is mirrored on the TV and with fullHD resolution capability, watching on an HDTV is a joy.
The power/lock button on top of the Butterfly S doubles as an IR blaster, and can be used to control TVs and set top boxes (not to transfer data like in the old days).
On the user end, the TV app lets you to control TV's and tuners from a wide variety of manufacturers. You can even get a TV guide in most areas just by entering your postal code.
The HTC Butterfly S comes with the latest version of the Sensed-out Android web browser. Most of its UI is out of sight, leaving the entire screen to the web page. And even when it does appear it consists of a single bar, which now holds the address field, the Tabs and Menu dropdown shortcuts.
Once you select some text, you can copy it, do a Google search with that text as the query or share the text over a message or social networking. Pages reflow to better fit the screen and you can set things like default zoom, search engine and URL suggestion providers and so on. From the Labs setting you can enable Quick controls.
Tabs can be closed with an X button in their top right corner - they can't be swiped off the screen like you do in the app switcher. Incognito tabs are available if you want to browse without leaving traces. There's also a popup blocker to stave off annoying popups.
If you prefer, you can also request the desktop version of a site instead of the mobile one. Another cool feature is preloading search results that the phone believes are relevant, speeding up the whole process.
The HTC Butterfly S comes with full Flash support in the browser (it's disabled by default). We tested a couple of games and videos and everything worked like a charm. Flash has almost been weeded out of the mobile web, but there are still a few stubborn sites around so it's good to have.
Interestingly, while digging through the settings menu of the browser, we found that there's an explicit setting for GIF animations, which is disabled by default. The GIF format on Android has a spotty history, but the Butterfly S browser does support these animations, as long as you enable them first.
The Google Chrome browser also comes preinstalled on the HTC Butterfly S. Its interface is easier to navigate but it doesn't offer Flash support. On the up side, it can synchronize the tabs you have open in other Chrome browsers (on a computer, tablet, other phone, you name it).