ChatSecure Messenger funktioniert nicht

Other apps may make claims about 'military grade' security but, without publicly auditable source code and verifiable end-to-end encryption, you cannot be truly safe. * OTR for verifiable end-to-end encryption and forward secrecy.  ChatSecure is a free and open source messaging app that features OTR and OMEMO encryption over XMPP.  Unlike other apps that keep you stuck in their walled garden, ChatSecure is fully interoperable with other clients that support OTR, OMEMO and XMPP.  ChatSecure only uses well-known open source cryptographic libraries to keep your conversations private.  Subscribe to ChatSecure to help make developing free and open source privacy tools sustainable.  The donation levels are currently $2. 99/month, $5. 99/month or $19. 99/month. • Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period.  You can create new accounts on public XMPP servers, or even connect to your own server for extra security.  We welcome any contribution to support ongoing development.  Your iTunes account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal. • Payment will be charged to iTunes Account at confirmation of purchase.