Ridiculous pricing. Acrobit Groundwire mobile SIP client [0] costs $10 once and is EU based therefore GDPR compliant. Add a prepaid SIP provider, mine charges less than $10/year for the number plus calling costs that are so low I don’t notice then. Once in a while I add $100 credit to my SIP provider, good for several years with 3 numbers. For incoming calls Groundwire send a notification that pops up the app and shows the UI. Works flawlessly, many options for deniing calls, forwarding etc, etc.

Some numbers are shared with others, just disable it on my phone and the other person enables it to start receiving incoming calls.

I really don’t see the business case for paying $10/$15 per month.

[0] https://en.wikipedia.org/wiki/Acrobits