SPIN/HOSN-app: An Android app builds on top of Twitter and provides users with additional means of privacy control. @ bf25e5f8d1c1f946423b2263e475680146d4b5a9

Carsten Porth 74f79e564b Fix typos, add captions		5 lat temu
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dapps.tex	a9376f6892 restructure background chapter	5 lat temu
p2p.tex	47de1a2eea Add section about peer to peer networks	5 lat temu
software-system-architecture.tex	74f79e564b Fix typos, add captions	5 lat temu