Adamsmashem
"its hard to get people to use the app"
bully and ignore your friends and family until they use it :)
I'm not familiar with qksms, what some use VOIP numbers: MySudo, twilio, etc. Where you can use multiple phone numbers and compartmentalize them for different things e.g., work, personal, medical, etc etc. When you do this, your SIM card is strictly being used for data, as you do not give out your actually SIM card number. VOIP numbers use internet for communication, not the traditional "mobile SIM network" for lack of a better term. Although as long as you are using your SIM card for data, you are hitting SIM towers, but technically (From my understanding) it is a different system as compared to how text and calls route through cellular networks. Although VOIP numbers are still unsecure communication, the compartmentalization allows you more protection from data breaches effecting multiple personal accounts as well as helps reduce the effects of data collection (because not all of your life is linked to a singular number). If one account with one number is breached, it won't effect your other numbers, etc. VOIP number downsides are that not every institution will accept them (banks most often). They also give you more protection against SIM swap attacks. MySudo does not require ID verification and Mint Mobile does not require ID verification, so although you won't stay "anonymous" long term (it's pretty much impossible with any phone number), the number won't be tied directly to you on paper. I mention this because I believe they are a more private and better alternative to SIM numbers. VOIP numbers are used as regular SMS numbers, you can text, call, etc to both VOIP and non VOIP (SIM) numbers. For people you communicate with on a constant basis (close friends and family) request that they use Signal, everything else gets a VOIP number.
MySudo in their policy also states that they hold your data for (i believe it was 24 hours) post deletion, after that it is gone, text, call logs, etc. Still, secure communication is preferable if possible.
I write this not to jerk off MySudo, but so that you understand different possibilities of cellular communication.
Also, as far as app privacy goes, if you use Private DNS and a DNS provider like NextDNS or (insert other custom filtering DNS provider here), you are able to see the telemetry (outbound analytics data) that apps give off when you open them and block them. Often, Apps send back home things like data analytics, crash analytics, etc. So while an app may only technically need connections 1-3 to work properly, 1-10 are being sent out. With custom DNS you can go in and black 4-10 if you choose to. This does not mean by doing this that all apps are safe all of the sudden, you can still download malicious apps, but it is an extra step some take after downloading trusted apps to ensure tighter levels of privacy.