Well, battery life will suffer... it's just like metalayer-crawler. But it should work, even without cron. Either start at every boot, or let the user manually run it when they want. slocate can run without cron.

Oh wait, I'm thinking like a slackware , or worse, a UNIX man.
This is debian, so slocate package must depend on cron, because you typically want to run it that way, and you can't have a package that requires the sysadmin to, you know, admin the sys...

I'd gladly take such a thing, if you could get it with no cron dep. It'd be useful to me if I updated the db once a month, because I'm usually hunting some system file, which don't change much.
Though it occurs to me, the tablets need something like anacron, only power-supply aware. If the tablet's charging (and the battery's over, say, 30% full), and it's been over <24hrs | 1 week | 1 month> since the task was last run, then re-run it... Be a good project for me, when I get time