I see that the only reliable way to fix problems, caused by F-Droid specific builds (that aren't even tested before a release!) is to create in F-Droid new "ToDo Agenda" app with its native package name and no changes from the app that I build myself, except for package signature (made by F-Droid).

In addition, I plan to drop support for Android before v.7.1.1 (API 25, the same as noted here: https://en.wikipedia.org/wiki/Android_version_history ), so it will be logical to leave old app for users with older devices.

metadata/com.plusonelabs.calendar.yml

@@ -5,8 +5,20 @@ SourceCode: https://github.com/andstatus/todoagenda
 IssueTracker: https://github.com/plusonelabs/calendar-widget/issues
 Changelog: https://github.com/andstatus/todoagenda/blob/HEAD/README.md#changelog
 
+Name: Todo Agenda for Android 4 - 7.0
 AutoName: Todo Agenda
 Description: |-
+    This is a legacy ToDo Agenda app (ex. "Calendar Widget") for Android v.4 - 7.0
+    It is intended for users having older devices. For newer releases please use "Todo Agenda" app.
+
+    Since November 2019 the app changed its ID in F-Droid from "com.plusonelabs.calendar"
+    to "org.andstatus.todoagenda" i.e. to its current real Android package name.
+    The new app at F-Droid web site: [[org.andstatus.todoagenda]]
+    Upcoming releases of the new app will support Android 7.1.1+ only.
+
+    The name of the new app entry in F-Droid stays the same: "Todo Agenda" (because the app itself isn't changed).
+    But the name of this legacy app entry in F-Droid is changed to "Todo Agenda for Android 4 - 7.0" to avoid users' confusion.
+
     Todo Agenda is home screen widgets for your Android device.
     It displays a list of calendar events and tasks
     so that you can easily have a glimpse at your due, current and upcoming appointments.

metadata/org.andstatus.todoagenda.yml

@@ -0,0 +1,49 @@
+Categories:
+  - Time
+License: Apache-2.0
+SourceCode: https://github.com/andstatus/todoagenda
+IssueTracker: https://github.com/plusonelabs/calendar-widget/issues
+Changelog: https://github.com/andstatus/todoagenda/blob/HEAD/README.md#changelog
+
+AutoName: Todo Agenda
+Description: |-
+    Todo Agenda is home screen widgets for your Android device.
+    It displays a list of calendar events and tasks
+    so that you can easily have a glimpse at your due, current and upcoming appointments.
+
+    Features:
+
+    * No advertising. Free and Open Source.
+    * Displays all events from your calendars and task lists. Optionally shows past events.
+    * Automatically updates when you add/delete/modify an event. Or you may update the list instantly.
+    * Select only the calendars you want to see in the widget.
+    * Create several widgets, if you need. Each widget will have its own settings, including layouts, colors, filters and selected calendars.
+    * Customize background colors and transparency of different widget parts, text's black and white shading.
+    * Scroll through the list of events. Use "Go to Today" button to return to today instantly.
+    * Customize the text size of the widget.
+    * Fully resizable widget with alternative layouts.
+    * Indicators for alerts and recurring events.
+    * Lock time zone when travelling to different time zones.
+    * Turn off Widget or Day headers, event icons, Days from today, etc. and see only what you need.
+    * Android 7.1+ supported. Supports Android tablets.
+    For the older devices please use "Todo Agenda for Android 4 - 7.0" app [[com.plusonelabs.calendar]]
+
+RepoType: git
+Repo: https://github.com/andstatus/todoagenda.git
+
+Builds:
+  - versionName: 3.1.7-560
+    versionCode: 560
+    commit: 3.1.7
+    subdir: app
+    gradle:
+      - yes
+
+MaintainerNotes: |-
+    Upstream generates CV and CVC from git, so we don't catch that anymore,
+    see https://github.com/plusonelabs/calendar-widget/issues/210.
+
+AutoUpdateMode: None
+UpdateCheckMode: None
+CurrentVersion: 3.1.7-560
+CurrentVersionCode: 560