If you're sure you don't want to be part of the Onlife journey any more, we undertsand. Let us know via support and we'll arrange cancellation. https://help.on.life/portal/en/newticket
You can certainly open Onlife every day and see what's in store - we encourage it! To amend events you'll need to use your normal calendar app - but as you already know it doesn't give you the full picture, so why not see what Onlife can do for you ...
Our first offering brings your calendar and map together to gove you more clarity and control over your day. For now it's mostly a visual and information tool on where, when and how long you have between meetings. There is plenty more to come ...