What's a good Android app for messing about and creating some tunes while I'm waiting for my bus in, say, Bangkok or somewhere?

Honestly, Drum Pad Machine has been an absolute godsend on some of my travels. I'm no pro musician, mind you, but it's brilliant for just messing about and creating some noise when you're bored. It's proper useful for killing time on those long bus journeys across Southeast Asia, or when you're stuck waiting for a delayed train in Italy. The sound packs are pretty decent, and you can even record your little masterpieces. Plus, it doesn't eat up your roaming data, which is always a massive bonus. It's not going to win any awards, but for a free app that lets you make a bit of a racket, it's sorted me out more times than I can count. Definitely worth a download if you fancy yourself a bit of a beatmaker, even if it's just for a laugh!