Please contact me by mail. I can't help and reply, when you write only an App store comment! See user feedback below.

To improve sound quality, use an external Sound Module or for example the App Roland "Sound Canvas". All instruments of the "Sound Canvas" (SC-8820) are selectable. You can map all 128 GM instruments to other SC-8820 instruments.

Features of the "MIDI file player/recorder":
- MIDI files must be in the shared iTunes folder
- Plays MIDI files
- Records MIDI files
- 10 play lists (add, remove and move items)
- Auto next and random playing (MIDI file list and play lists)
- Loop function (wait time is adaptable by long pressing on loop button)
- MIDI Bluetooth LE supported (e.g. Yamaha MD-BT01)
- All instruments of the Roland "Sound Canvas" (drum set included) can be mapped to the General MIDI instruments.
- Plays and records at the same time e.g. for muting channels in a MIDI file
- Can be used as virtual instrument for your MIDI master keyboard, MIDI accordion etc.
- Plays and records additional instruments at the same time (needs MIDI interface like "iRig MIDI" and a MIDI instrument)
- You can change instruments, volume, reverb, chorus and panorama for each channel
- Transpose MIDI file (-5 to +6 half tones)
- Local sound ON/OFF
- MIDI Thru ON/OFF
- Show system exclusive messages (SYSEX) ON/OFF
- Filter SYSEX messages ON/OFF
- Notify text field for informations
- Easy file selection and possibility to find or rename MIDI files
- Send MIDI file by Mail
- Automatic file import (e.g. from internet), when you chose "open in MIDI player"
- Customer "SoundFont" can be placed in the shared iTunes folder. The name must be "GM_instruments.sf2" and it must support the general MIDI sound set including drums. Large "SoundFont" files may not work. Use very small "SoundFonts", when you have an older iPhone or iPad. For this devices you can try e.g. the "bennetng_AnotherGS_v2-1.sf2"
- Integrated Help
- Background playing
- 32 chord types are detected and displayed
- The chords can be detected on all channels or only on a specific one

Known problems:
- No sound: Is the silent switch set to OFF or volume too low?
- MIDI files using nearly all 16 channels and a lot of resources may not sound correctly. Try to mute some channels/instruments. This happens only, when using "Local sound" and some instruments (e.g. strings, synth pad, effects).
- The sound quality is lower for older iPhones and iPads due to the smaller SoundFont size. If some MIDI files do not sound correctly, please use a small SoundFont like the "Scc1t2.sf2". On some devices (older iPhones or iPads) the "Bagpipe" sounds wrong in my ears.

Some user feedback:

Perfect * * * * *
by Altoblues – Apr 11, 2018
A really useful app for choir members. The ability to mute some parts, transpose, and alter the pace of the music is great.

Fantastic * * * * *
byMoorlander - Sep 13, 2015
That said, not found any better apps for the function (and I've tried 6 now, free and paid), so great work, many thanks!

Coconut Ron's MIDI file player review. * * * * *
von Coconut Ron - Version - 1.1.8 - Aug 17, 2015
This app is worth every penny. Just what I was looking for without any snags.

:) * * * * *
von SNOWTIMEANGEL - Version - 1.1.6 - Jan 10, 2015
I like this app VERY MUCH. Ideal for learning choir parts, which is how I am using it at the moment. Customer Service is ABSOLUTELY EXCELLENT. Great Value.

Great App! * * * * *
von Ungeheur - Version - 1.1.1 - Feb 17, 2014
This is one of the most useful apps I have run across. Far more useful than a simple player. It's ready then to be used as my "accompaniment" when I play along with my trombone. Thanks for a really useful app!

Plays MIDIs Perfectly * * * * *
by ClarkJacob4 - Version 1.0.1 - Sep 6, 2013
Plays MIDIs perfectly, and it's a very good price. File manager has import feature from my other apps which is excellent as well.