From VoIP.ms Wiki
A smartphone is a handheld, mobile device which integrates a personal digital assistant (effectively, a small computer) with a cellular telephone. Many common devices in this category run Google's Android operating system; Apple's iPhone devices run their own Apple-proprietary iOS.
While most of these devices already are mobile telephones, installing a softphone application (typically a free download) has cost advantages; wherever a Wi-Fi signal can be obtained, a call using voip.ms is typically more than an order of magnitude less expensive than a mobile telephone call. Wi-Fi is also convenient when travelling; a handset which is otherwise completely dead in the visited country (on the wrong local mobile frequency for the continent, or locked to a carrier which does not allow roaming) will still make calls using the Internet. Many hôtels and cafés include open Wi-Fi for their clients in the basic price of their service, with budget hotels less likely to charge extra for network access. A call from Wi-Fi is often less expensive than either the telephone in the hotel room or a roaming mobile telephone, especially for international or overseas calls.
A few devices have every smartphone-like capability except telephony; the iPod Touch is one example of a handset-sized device with Wi-Fi and all iPhone capabilities "except the phone". A few tablet computers also fall into this category. These often have pre-installed applications for webcam chat with other Internet users, but downloading a softphone and configuring it to connect to voip.ms turns them into full-fledged telephones wherever a wireless Internet connection can be found.
The app itself is often a free download, the calls incur the standard voip.ms rates. The calls will go through even if the handset is not subscribed to any mobile telephone provider, just so long as Wi-Fi is available. Most often, the app by default loads automatically on startup and runs in the background to listen for incoming calls; if only outbound calling is desired, it is advisable to disable any "load on startup" and "run in background" options in the application configuration menu in order to conserve battery by not keeping a Wi-Fi connection open when idle.
The least-expensive commodity Android smartphones often cost much less than purpose-built wireless SIP phones such as the 3COM 3108 Wireless Phone or Pirelli DP-L10 but provide the same functionality, right down to the look and feel of a mobile telephone. No need for a microphone or headset (as commonly used to improve sound quality on desktop PC softphones) as the device already is a handset. Prepaid "no contract" mobile networks have flooded the low end of the market with under-$100 Androids which are more than capable; the low-end model typically has a smaller screen (as a media player) and lower resolution (as a digital camera) but works well as a SIP phone.
VoIP.ms users who already have a home or office telephone in use on their main account need only add a sub-account to obtain a separate login for a mobile device. It is possible to configure ring groups to have incoming calls ring a main (desk) phone, the mobile smartphone or both on a per-number basis.
Most of these applications are free downloads from Google Play, but must be configured before use (to set a userid, password and server name). See the individual application articles for setup instructions:
- Android Sip Client, bundled with Android 4.1.1
- Grandstream Wave
- NetDial Sip Phone
- SIP Droid
- ZoIPer for Android
- Some older versions of 3CX Phone may work; this is broken as of version 11 and version 12.
- Idoubs Phone
- NetDial Sip Phone
- Zoiper Mobile (App) (ZoIPer for iOS)