OpenSunsama is the best open-source task manager
opensunsama.com
opensunsama.com
The design taste is impeccable.
saying if only I try it I'll agree with you has the opposite effect you want
The or was intentional, I would also point out that selling does not always mean convincing someone to trade money for something. For example, here I am trying to sell you on the idea that selling is more general.