"Tasks for life" - Would such a phrase be apropriate for a brand ? Is it correct to say it that way ? I want to create a task managing site, where people would manage their tasks in life.
PS: English is not my native language, so please, excuse me.
With all the little info you've provided us with, I'd call it:
The above phrase is pretty clear and powerful, while your original phrase, tasks for life is ambiguous, as it may either mean:
1) tasks for life (the usual, simple meaning)
Having an ambiguous phrase in this case isn't really anything one usually wants, therefore I'd recommend avoiding it.
Generally, "for life" typically means "for the rest of one's life." Even if people recognize that it's not your intended meaning, it's still a meaning that will occur to a native speaker.
It could be either negative (RiMMer's example above) or positive ("I'm struggling now, but if I win the lottery, I'll be set for life")
However, I don't think what you mean is "We'll give you more and more tasks forever until you're dead," so I think you should avoid "tasks for life."