Virtually all tuners nowadays are chromatic - they will tune to any note, not just a particular set of notes (such as EADGBE for guitar). They can usually be pitch-adjusted but as long as you make sure it's set on A=440Hz you're good to go. I have a Peterson Stroboclip which is very accurate and cost £75, but I habitually use a Snark which is accurate **enough** and cost £12 - so cheap I have six, one in each guitar/mandolin case and one lying around on the coffee table for easy access at home.

I don't use tuners which rely on hearing your instrument (such as phone/iPad/computer Apps) because, in a noisy environment such as a session or a pub, they're confused by ambient noise and, as such, they're as much use as a chocolate teapot.