Wouldn't it be better to simply start convincing your friends to use something more open, where you have choice of the client?
It feels like solving the problem from the wrong angle…
Ends up with some friends throwing you a bone and downloading / registering for a new service. Some of them remember to keep it open. Some use it. The rest of their friends don't. But a few of them love you enough to use a special app just for you because you seem to care. <3
Besides, what's more open, as usable and secure?
I'm sure if a third-party client would contribute to support the maintenance (both financially and in terms of the time and effort investment) he might be open to that, but obviously that's not going to happen.
Also I find it puzzling that so many people here keeps on recommending WhatsApp over Telegram after all the lies from WhatsApps owner.
Edit: While I have no way to verify this, AFAIK both Telegram and Gmail stores data and keys in ways that makes them hard to access by everyone except for the user.
Telegram in particular say they do this by storing data and keys in different datacenters in different jurisdictions.
Add to this that WhatsApp has had their fair share of issues as well before they started working with Moxie.
As a Russian, I do appreciate the fear that the "russki" brand instills in your soul, but I think you are rightly being downvoted for jumping to conclusions simply based on nationality.
But to be clear: I have a lot of distrust against governments regarding mass surveillance. But I distrust some governments more than others. And Russia is relatively high on that list for me. I think a healthy dose of distrust would be fitting for Russians citizens too.
It can take years, much like a car has to be crash tested, a new crypto algorithm must go through a certain process to be considered good enough.
That said: I belive them when they say that WhatsApps crypto is stronger.
On the other hand I would expect them to leave a little note somewhere about WhatsApp being a data collection tool for Facebook that also still happens to works as an instant messaging platform.
People like tptacek have talked here at length about why Telegram is not trustworthy, you can see a history of his comments with a simple search: https://hn.algolia.com/?query=tptacek%20telegram&sort=byPopu.... Moxie Marlinspike has also pointed out a bunch of problems with Telegram, and even if you don't consider him a trustworthy source because he runs a competing service, the technical reasoning behind his opinions is sound.
If you want a personal POV, here are three reasons why Telegram is a bad idea:
1) The large number of unsound technical decisions. See Thomas and Moxie's many comments for details, or the "Security" section on its Wikipedia page.
2) Within days of launching, they had a critical security vulnerability: https://news.ycombinator.com/item?id=6948742. Frankly, this alone should have discredited them forever, especially considering how much boasting they were doing beforehand, but people are stupid.
3) They have a consistent pattern of responding to criticism not with technical defenses, but with ad hominem attacks and conspiracy theories ("You're paid by the US Government!")
I just don't want any more applications open.
I'm CA's will be bypassed soon. There's a lot of brain attention on this.
Just go XMPP with OMEMO, so no hard smartphone dependency, no electron app monsters. Thankfully XMPP doesn't have a problem with 3rd party and federation.
Telegram in my opinion is far better, it's completely cloud based, you can use it from whatever device you want, it has real desktop apps, you can send files, you have bots, channels, large groups, usernames, you name it.
I don't get why using Signal, yes it's free software, also Telegram it is (ok, the server is proprietary but even if you have the source how can you be sure that what they release is what is running on the servers ? If you don't run your own server the source are useless), but I don't see other advantages, so why bother with a third messaging app ? I use WhatsApp for the large user base, and I use Telegram for the advanced features if I need them.
Also, it has a much more praised security and cryptography than Telegram, is always encrypted (Telegram is only encrypted in secret chats) and has a much more secure codebase, with more open development (Telegram sometimes takes weeks to release source code), reproducible builds and a more transparent history.
I do use Telegram (mainly for group chats), but I treat everything posted in it as I would treat a public forum like HN.
It's self hostable or you can just login on their Matrix server.
Ah, and no phone number needed.