I think that one of the most effective tools for educators K-12 is the Google Calendar integrated into their Gmail account. You can easily access the Calendar Widget by enabling "Right Side Chat". The Calendar icon will appear in the top right. The student can close and open the calendar to view information while in the Gmail. Not to mention, using the Notes function as well.
Today's learners whether they attend in-person 50% or full inclusion, will need to learn better time management skills. Especially when collaborations are needed on projects. As a teacher, I can post Google Calendar deadlines for projects/tests/assignments and then let the kids enter their own deadlines or activities for them to better manage their time. For example, a high school student in an extra-curricular who needs to be studying for a test in Calculus and coordinating with peers on an English paper. This can also extend to outside of the classroom allowing parents to view the same deadlines when the calendars are shared with other family members. Lastly, the Calendar moves between Android and iPhone so it is the most portable.
See
https://www.youtube.com/watch?v=IyHvKYeeuB8 (learn how to setup)