This talk offers a walk-through of the main PWA features and a comparison how they behave across different platforms (Linux, Android, iOS), on various web browsers (Firefox, Chrome, Safari). Practical code examples will come from Sojourner - a FOSDEM conference companion app. We will also discuss some UX/UI challenges and their potential solutions specific for PWAs. During this talk we will discuss the following aspects of PWA and illustrate them with practical code examples. Performance and network reliability: Service Worker strategies Offline-First operation Persistent Storage: availability, limitations, access request no login required Installation: In-browser via Add to Home Screen (A2HS) From app-store Design: choosing the right design system handling colors, icons and screen mode gracefully At the end we will summarize the state of PWAs in 2020 and for which types of applications they work best. Examples used to illustrate this talk will come from Sojourner FOSDEM conference companion app, written using Vue.js framework.