I have tried almost every VOIP soft phone app on Google Play. Before I found GS Wave, I reckoned Zoiper app was the best soft phone, thus I paid for its premium version to get its premium feature of video call.
However I never got this feature working. I wanted to see the video from my video door phone on my mobile with Zoiper. My video door phone supports H264 video codec but Zoiper supports VP8 unless I pay Zoiper again just for H264 codec . Unlike audio codec while a VOIP server can translate audio codec between clients, video codec is said to be P2P. (There may be a way of video codec translation, but I don’t know how.)
I had video calls working between my video door phone and desktop SIP phones which are “hard phones” with H264 built in. And I had audio calls working on all devices. So I was not desperate for video on Zoiper.
Zoiper has a major defect. It cannot stay online 24/7 on latest Android version (I tested on two Huawei Mate 8 and one P9) or iOS. Many times status bar shows it is online but actually it is not reachable. Zoiper was reliable on Android 4.x.x. I guess Zoiper “forgets” to re-register itself when OS goes into sleep. For above reasons I am reluctant to pay Zoiper any more money.
Recently I visited Fanvil website and discovered Fanvil had developed a soft phone called “Vdroid” for free download. To my surprise, Vdroid integrated G729 audio codec and H264 video codec. They are premium codec as on Zoiper. (Later on I learnt G729 patent expired on 1st Jan, 2017 but Zoiper is still selling G729 for money. I knew nothing about H264.) However Vdroid has too many bugs and is not a mature software.
Then I thought other VOIP device manufacturers might have their own soft phones for public. I checked Grandstream, Yealink and Cisco but only found Grandstream generously offering GS Wave. GS Wave has both Android and iOS version, and both works reliably, and both has G729 and H264 built in for free! I cannot wait any longer to recommend GS Wave to everyone. Google Play is overwhelmed by other apps for search results of “sip” or “voip”, and GS Wave is nowhere in the ranking. But trust me, it is the best one.
正嗟叹中，朋友告诉我，华为应用商店里就有 Google 框架下载，安装好就能像国际版一样用 Google 服务了。有这等好事？我想起之前 Grandstream 也是如此迂回战术，但没想到华为也会。我赶紧上华为应用商店看，还真有一个叫”谷歌框架安装神器”的应用。我拿老妈的一个国行手机试了试，很顺利地装上了 Google 框架。我又拿它来给 Fanvil D900 Android IP Phone 安装 Google 框架，也很顺利安装成功（安装之前要 root D900）。D900 买了两年，一直觉得是鸡肋，就是因为它无法用 Google 服务，当时我频繁联系了 Fanvil 技术支持，他们给我发了好几个 firmware 去更新，都没有成功装上 Google 框架，后来我自行放弃。如今被华为的”谷歌框架安装神器”一举解决，我怎能不兴奋。（不过今天后来我在 Fanvil 官网上下了最新的 D900 firmware，更新后发现此次的 firmware 已带有 Google 框架，只是 Google Play 未安装，但在根目录下存了一个 Google Play 的 apk，安装一下就好了，也无需 root。）
总之，华为能提供 Google 框架，让我对入手国行华为手机再无顾虑。顺便我看了看小米应用商店，没有提供 Google 框架，那就多劝人不要买小米呗。
I dream for an Android app which can make mobile serve as a GSM gateway. In many scenarios I need such an app.
I am abroad but I want to make calls to and receive calls from the UK contacts. I can leave the mobile in the UK on a charger, then connect to the mobile via Internet when abroad, via SIP protocal probably.
Call plan of mobile phone contract has unlimited calls included, so I perfer to make calls via GSM network. But I also like to talk on the desktop IP phone, which make my business look professional.
In other words, I need an IP PBX app for Android, but no one made it available. Many apps of SIP client are on the marketplace, but no SIP server.