Threema is based in Switzerland, and offers an iOS and Android client to let users send messages to each other. The service features end-to-end encryption, so messages and passwords are safe. Threema features optional manual key verification, which means that users can verify that they are speaking to each other so the connection is trusted. Otherwise, the feature set is that of a good messaging app: filetransfers, location sharing, media sharing, it’s all there. The app costs $2.