@JOduMonT First off, that site is just reviewing app permissions. It’s docking Signal for requesting things like access to camera (used for taking and sending photos). That’s not really relevant here.
From a security standpoint, the Signal protocol is the gold standard for secure messaging. Other apps , like WhatsApp have even implemented it themselves.
Signal is also a non-profit and spends a considerable amount of effort in reducing knowledge needed to operate on the server. Their goal is to get to a point you don’t have to trust the server at all.
I have never heard of the app you’re recommending, but I don’t see any information about how they manage their encryption. Their website link (from Google Play) lands on some obscure website that doesn’t really load unless I turn off my tracker blockers. The site then doesn’t really indicate why I should trust them. No information on their funding or security. Also, the Play Store listing says it includes Ads. Which is a huge no-no for privacy.
Telegram is a popular app, but Signal is often recommended for security/privacy. First off, Telegram offers both encrypted and unencrypted messaging and defaults to unencrypted. Group messages cannot even be encrypted at all. In Signal, all is encrypted. Furthermore, when using encryption, Telegram uses a custom crypto algorithm they wrote rather than industry trusted ones like Signal does. This goes against a common maxim in the security industry “don’t roll your own crypto”. It could be just as secure, but less eyes on it means we just don’t know enough about it. Most professionals prefer a tried and true system.
Anyway, I’m pretty passionate about secure messaging, so I’ve done a bit of research here. All that said, unless they are willing to switch, the best one is the one your friends are using. Messaging is useless if you’re the only one with it. Kinda relates to the article will posted about encrypted email in the first place.