Idea for a selfmade mini iPad midi-controller?

Hi. I would like to create a mini live-midi-controller for my iPad (connected via bluetooth) with only some basic functions.
a) choosing a song
b) setting tempo (not as a midi clock, no tap-tempo), only by typing numbers
c) if possible increase or decrease buttons
Thats all.

I play guitar in an acoustic-cover-duo. We dont have a fix setlist.
For live use i have two folders on my beatbuddy.

  1. contains at the moment 18 Basic-Beats, for most of our songs. For these i have to adjust the tempo individual before starting the beatbuddy.
  2. contains songs with special patterns (no tempo adjustment necessary)

My partner and me are using forscore for our Chord-sheets. Forscore can send midi commands for choosing songs, but not for tempo. I know Onsong will do these commands, but i dont want to change from forscore. The same commands sends quantiloop (very comfortable), but i dont want to run a looper-app parallel to forscore, only for some basic beatbuddy-commands.
I have a midi-creator app TB Midi Stuff, and i succeeded in making buttons for choosing songs. The tricky part is the tempo. I dont know, how to program the midi commands described in the beatbuddy midi-manual. Can someone help me, or give a suggestion for a little app which can do this? Touch OSC or Midi Designer seem to be very big for my wishes.