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Class Timetable Pro for schoolers and students.
Easy to set up app that allows you to know when the lesson starts or when will it end in time.

App features:
1) Tells you the time till the lesson's end
2) Gives you timetable templates
3) Adds new timetable widget
4) Features sharing timetable with your friends
5) Has week presets to customize your days
6) Shows notification five minutes before the end of the lesson
7) Helps you to skip unneeded classes to the needed ones, Yay! XD
8) Is the only one having feature of switching timezones without changing system time zone.

Problem solving:
Schedule files are not saved, schedule cannot be shared. Requires permissions to write files.
Notifications do not appear on the lock screen, vibration and sound do not work. Configure notification permissions for the app. Settings - Apps - Call Schedules - Notifications.
The time on the lock screen does not change. Time changes but the system does not delete old ones on time, for this you need to go to Settings - Battery - Launch applications - uncheck the "Call Schedule" box, a window will appear, press ok.