Designed from the ground up with the mobile user in mind, Groundwire is the first mobile SIP Client capable of replacing your desktop phone. Combining all the features business users need (see below) with intuitive features created with the mobile user specifically in mind (number rewriting, address book matching and more), Groundwire will quickly have you wondering how you survived without it before. Check out the tutorials and knowledgeable articles at the links below: https://www.acrobits.net/hesk/knowledgebase.php https://forum.acrobits.net For the list of providers and VoIP services tested with Groundwire, see http://www.acrobits.cz/about-us/partners#tab_verified-voip-operators And check out https://www.acrobits.net/products/retail#tab_softphone for a side by side comparison of the most popular features of Acrobits Softphone and Groundwire. *CallKit support! *Push Notifications for long battery life *Video Calling - H263, H264 and VP8 codecs *Multi line *Call conferencing *Transfer and attended transfer *Call waiting *Voicemail Notification and programmable Voicemail dialer *ZRTP support (through in app purchase), the latest in secure calling for SIP *enterprise support for SMS through SIP SIMPLE *SMS support for betamax providers, pennytel and sipme *backgrounding support *Call recording (only available for SIP calls, will not record calls from your GSM line) *Bluetooth headset support (iPhones, iPad 2+ and iPod Touch 4+ only) *Customizable ringtones *Quickdial, your favorite contacts only one tap away *Number rewriting, edit your existing contacts for SIP dialing without creating additional entries and program specific number to be dialed through specific accounts automatically *in-call quality indicator, see network quality, packet loss and jitter *Background noise suppression *Quick import of accounts from major VoIP providers including sipgate, callcentric, voipcheap and many more. *TLS support for encrypted SIP *SIP Proxy Support, VPN Support (configure VPN in iOS settings) *Excellent sound quality, supports OPUS, G.722, G.711, iLBC and GSM. Make an in app purchase to add G.729 for great performance over 3G networks *SIP Log for troubleshooting Groundwire fans, please rate Groundwire or leave a review. If you have an issue with Groundwire, please contact our support even if you leave a review stating the problem. We are unable to respond to reviews so even if your issue is simple to resolve, we have no way of letting you know. Groundwire is highly configurable so problems that seem insurmountable may just require a couple of adjustments to the settings. ***NOTES - IMPORTANT, PLEASE READ*** SIP - Groundwire is a SIP Client, not a VoIP service. You must have service with a VoIP provider or PBX that supports use on a standard SIP client to use it. VoIP over 3G - Be aware that some mobile network operators prohibit or restrict the use of VoIP over their network. They may prohibit the use of VoIP or impose additional fees and/or charges when using VoIP over their network. By using Groundwire over 3G, you agree to abide by any restrictions your cellular carrier imposes and agree that Acrobits will not be held responsible for any charges, fees or liability imposed by your carrier for using Groundwire over their 3G network.