Finally i found out how to perform BPM correction on android. :-) Problem could be fixed in few minutes, but i didnt noticed that i have that app. I never thought Audio Evolution have this fantastic time stretch option. I bought it few months ago and i was like: hm, okay. This app is just for synchronisation. Other options? Naaaah.
Anyway, you should have this few things.
1. Paper and pencil
2. Basic knowledge about math
3. Acapella and original version of song
4. Audio Evolution Mobile latest version.
1. Check on internet what is BPM of song you want remix. It is 128BPM for example. Okay, and for example you wanna make dubstep remix which BPM is 140. Get your paper and start calculation.
2. You need to know rules of proportion. If 128 BPM is full speed, lets just say 100% of speed, 140BPM is how many % ????
Correct answer is 109.375%
So? What is that mean? That mean you need to speed up audio for 9.375%
3. Go to Audio Evolution Mobile and import both (acapella and original) , set tempo on 128. Turn on Grid option, just to see where bars are. Now manipulate with original version of song. Move it through grid bars and make beat fits perfect with bars. Now synchronise acapella with original sound. Until you dont hear one perfect sync voice from 2 sources. Now you have acapella syncronised with the beat and bars. PS....You can import some drum patterns besides metronome sound. To have better view about sync. Now you are ready for final step.
4. Long press on audio track and choose offline fx or something like that (i still cant believe i didnt noticed these options). :)
You will see option time stretch. Click on it.
There is some value. Like 1.0 That means there is no change in time. If you want to speed up tempo you should make 100% minus 9.375 which is 90.625% In this case you should enter new value. Not 1.0 anymore, now is 0,90625
Click on apply and wait. Now is time of audio compresed and tempo is faster for 9.375% which is 140BPM
Hope this can help to you. ;-). I made correction from 91.1 to 91
A lot of numbers in % but it works.