@Techaltar @protonprivacy One can see the web overlay and could use that in e.g. an Ionic application (like they do on Linux with the Proton Mail + Calendar app) or maybe Tauri would work. Also, an old fork of the calendar UI for Android in Kotlin is public and some old React Native version (?). Proton does take user requests systematically with UserVoice.
@Techaltar @protonprivacy However, even though the requests are sometimes marked for planned or not, what will actually come in what time spans is not really transparent. Even though Proton Wallet was planned and prepared apparently for a long time, its publication still took many users by surprise.