Cadence.FM (free) is an excellent iPhone app that compliments your workouts by providing you with a constant streamof music that consistently matches a chosen tempo — it’s your “on-demand personal DJ.”

Its best feature is that all of the music it plays is streamed from the SoundCloud music community and includes the best popular remixes, trance, house, dub-step and club music — so you don’t even need to store tracks locally on your device to use it. Just choose a channel and specify the BPM to which you’d like to work out and Cadence.FM will select the music for you — and it does a great job of it!

At the top of this week’s list of must-have iOS apps is the awesome comic creation tool that previously came bundled with Intel Macs. Comic Life from plasq allows you to use the photos in your iPad’s camera roll to create your own comic masterpieces.

Notificant is a brilliant new productivity app that makes is fast and simple to create reminders for the things you’d usually forget. Choose to have notifications alert you on your iPhone, as well as any of your other iOS or Mac devices.

Exploring your music collection has never been as stunning as it is with Planetary – a free iPad app that has climbed rapidly to the top of the free app charts. Fly through a 3D universe dynamically created by information about the recording artists you love.

Find out more about the applications above and check out the rest of this week’s must-haves – including Cadence.fm and 4oD Catch Up – after the break!