NOT ON THE LIST IN 2020
Threema end-to-end encrypts all your communications
Website: threema.ch
Cost: Commercial
Availability: Download app
Overall rankings in the 14 surveys: 2007-2020
2020: – | 2019: – | 2018: – | 2017: 131 | 2016: – | 2015: – | 2014: – |
2013: – | 2012: – | 2011: – | 2010: – | 2009: – | 2008: – | 2007: – |