(Help) Surespot security and how to talk via mobile in a safe way?

Hey guys, one of my friends suggest me to get surespot on my phone in order to chat with him in a safe way. However you may already noticed, I’m paranoid.

I don’t trust my mobile device at all when it comes anonymity.

If you do, what do you use via mobile to talk in a safe, private way, that doesn’t leave traces on your mobile (like temp data or shit like that)?

Do you think surespot is safe? Btw this is their website: https://www.surespot.me/

I prefer 100 times talk behind Whonix with pidgin + otr of course…

i dont think u will find any phone that provide anonymity. not because of the apps but because of the phone operating system itself.

Android OS? made by google so u can imagine …(even if u gonna say its open source , there is no company claimed to give u anonymity. security maybe but not anonymity. for example:- blackphone?)

Sailfish OS ? used to be on jolla phones = not much different than google but its better for sure. anonymity ? i dont think so. read their policies.

IOS ? made by apple so u can imagine …(closed source = no way of anonymity)

Windows Phone? made by microsoft so u can imagine …(closed source = no way of anonymity)

QNX OS? made by BlackBerry…(closed source = no way of anonymity)

Tizen OS? made by tizen in association with samsung &intel …(all the companies mentioned here have no relation with user privacy/anonymity. and the SDK (Software development kit) of the OS is closed source = no way of anonymity)

Ubuntu Touch OS? made by Canonical Ltd … (Canonical feed on your information , u can read articles about ubuntu and privacy. canonical = microsoft)

regarding the app itself , i heard about it but didnt read much about its company so i dunno regarding the app safety. but it has similar features like TOX chat. which i have read much about and i really advice users to use it. (dont relay on it for high private conversation because the app still under heavy development).

also dont forget to use on ur phone = Orbot +Orwall (orbot firewall).

so u can be anonymous with ur apps but not with ur phone OS.