This is a great play-along app by the talented drummer legend Peter Erskine who has been a big influence on me. An app where you can separately mute all instruments and an app which is well worth the money if you want to try playing alongside him and his great jazz trio.
Having a decent metronome on your phone is a must for drummers (as well as any musician) these days. The Metronome app is both very easy to use and free. It has a practice timer, a flashing light option as well as different click sounds to choose from which I find useful.
Polynome is a great and more extensive app than Metronome. Takes a little more tweaking to get used to, but has many great tools (eg. programming a set amount of muted bars or gradually changing the feel between straight and swung).