MidiBus

This app is the ONLY app I have found that will send a clock to Beatsurfer on the same device, and believe me I have tried them all! You are a lifesaver and I found before i managed to rip all my hair out!!!!!!!!

If you've ever had any problems getting different synth/beatbox/DAW apps to play in time together -- and really, who hasn't? -- then you need MidiBus. Does what it says: set the tempo (bpm) and time signature in Midibus and presto! Your apps will be synched to the same, accurate clock, even the really sloppy ones. To give but two examples: Thor and Sunrizer. Both these synths are capable of amazing sounds, and both have sequencers that refuse to play in consistent time and drift all over the place. Nothing worked, and believe me I tried lots of fixes. I just tried running Thor and Sunrizer sequences while playing Gadget (always reliable) simultaneously, all synched to Midibus, and I'm happy to report no drift whatsoever, running them for 10 minutes even. I really want to thank the developer. Rock solid MIDI clock is absolutely essential for music creation, and it's painful to see how sloppily it's been implemented on iOS up until now. Midibus will save you many hours of tearing your hair out.