100 participants for a review campaign? I think this will be the biggest review campaign on the forum as far as I know.
I hope that the reviewers will have the opportunity to test the service without paying a subscription, because I see that the price of the service starts at $100 per year. But, I will wait to see the exact conditions of the campaign.
Hi, from the Mixin Safe team. The price shows on the website are meant to be the pricing proposal when product fully launched.
For test, the price is very cheap, starts at $2 per year, and it includes a free transaction to send, so $2 is the minimum cost for a tester.
One thing I really don't like from start is that I have to use my phone number to use Mixin app

Think we already talked about the product in the ANN topic. For the test, I believe you have no need to worry about this. Before the anonymous number feature is fully rollout, you may use some phone number services on the Internet to get a random phone number just for a single SMS. Then you can begin the test, just you know that you may lose the account access because you don't own the random phone number, and if you like the product you can change the number to our Mixin Anonymous Number once it's launched in upcoming months.
Best