How can I reinstall version 2.6 if I already updated to 3.

So i just got done doing what u want done, because i wanted this too. here's what u do.
1. get an idevice with ios 6 on it.
2. i used my ipod touch 4.
3. download "better tube" and it will make u download the old mediaburner v2.6 because better tube is ios 7 and isn't supported on ios 6.
4. now plug that device into itunes and transfer purchases and the mediaburner .ipa will copied to your PC, the default location for the copied apps should be
\Music\iTunes\iTunes Media\Mobile Applications
it'll be called "mediaburner 2.6"
5. now download "ifunbox classic" http://dl.i-funbox.com/ it's the .zip file
6. now plug your iphone 4 or any new idevice u have and open ifunbox
7. at the top of ifunbox, there is a tool bar and one tool should say "install app"
8. click that and go to where the mediaburner 2.6 is located on ur pc and double click it and there u go. it'll only take a second to install, just make sure u don't update it again.
9. and if u can't get an a hold of an old idevice, then make a gmail, sign into google drive with that gmail and post ur gmail for me and i'll send u mediaburner 2.6 because i have a backup copy

oh. and i forgot to say that u can't restore purchases if u get the old mediaburner this way .-.
because apple can't see that u have the app installed. the app store won't ask u to update either, for the same reason. it goes unnoticed.
but if u have an old idevice with ios 6. then just re-download mediaburner on there using the itunes app store and use that device.
just make sure the old idevice has your apple account on it too.