We built the bulk of this while in-person during our SF offsite. When we went back to working remotely, we leaned heavily on Tandem to keep the fast, fluid conversation going. It almost felt like we were still in the same room. The high-fives are cool too :)
Biased because I founded Tandem, but it really is amazing to be able to jump into watercooler chats. We used Tandem heavily in getting this launch out, for quick syncs, brainstorms, and unblocking calls. My favorite feature is by far the High-Five™.