This update covers some major changes.
+Dark mode is available for iOS13 users.
+UI Optimisation:  Especially for iPhone  X and other devices.
+Send MIDI message: To all selected (or single) output destinations.
+Receive MIDI message: From all selected (or single) input sources
+Bug fix: No more crash while incoming MIDI messages.
+Timestamp is added,  Delta time is removed.
+MIDI Send tab is renewed.
+Now everything is faster than before.

+ Visual improvements for iPad and iPhone Plus devices.
+ Fix: Background mode back again.

+NEW "System Exclusive" message filter added.
+Now MIDI Clock can be filtered, no more crazy scrolling!
+DeltaTime column added. Now, you can see the time difference between the MIDI notes and messages.
+Design optimised for iPhone X compatibility.

+ MIDI Channel filter added: Eliminate messages comes from unwanted MIDI channels.
+ MIDI Message filter added: Eliminate unwanted channel and control messages (e.g. Note on, Note off, Pitch wheel etc.)
+ iOS 11 Compatibility updated.

+ MIDI Device Connection Info & Tips tab has been added. Some devices need some tips to connect in ease, now it's available in the MIDI Check!
+ Piano keyboard stability improved. (Rarely it could stick on a pressed note, fixed.)

Bug fix: Returning from background mode was causing duplication of incoming Midi-In messages. Now it show correctly.

+ MIDI Communication Message view completely renewed for better performance and visibility. Beautiful icon set and text formatting.