Estonian
The Estonian national gene collection project: https://www.geenivaramu.ee/en
I think they currently have 20000+ citizens sequenced(including me), and this year they hope to add 100,000 more.
The motivation to volunteer: They provide personal gene consultations for the donors and hopefully in the next few years it (the sequenced genome) will make its way to peoples personal doctors.
Although, I didn't know anything about them sharing it with the UK, Finland and Spain...wth