Is there a way to remove tasks or projects, that are marked as complete, so they dont show on my mobile device?
Please clarify - are you referring to completed tasks or project which you don't want to use anymore?
Completed tasks are removed unless they're sub-tasks in which case they're visible until their parent task is completed.
As for projects - you can enter edit mode (manage projects) and delete any project from the list. Please let me know what mobile version you're using (Android or iOS) for details on how to access this feature.
Android is the os, and now I understand how tasks and projects work. I also found that of you log off out will clear the completed tasks. I expected that a refresh would but it doesn't appear too.
To delete a project on Android, tap on "Manage projects" at the bottom of the project list and each project will now have a pencil icon on its right side. Tap on the icon next to the project you want to delete and then on the 3-dot icon in the top-right corner where you can select "Archive" or "Delete" from the menu.
When I archive a project, can I reopen or access it?
Archived projects may not be accessible through the mobile app, but you can access and unarchive it through the web-app anytime.
If you log into your Todoist account at https://todoist.com you'll see a "Show archived projects" link below the project list. It will show all archived project, you can browse them while they're archived and to unarchive it, simply right-click on one project and choose "unarchive".
Thanks for ask your help.