I plan to change my working machine and decided to go with mbp but I confused which one to choose, whether 13" or 15". Which one the most suitable for dveloping mobile apps?

Both will probably be fine but the 15" will have a bigger screen which will be helpful if you have a few windows you want to have open at the same time as you work.

@wiredgecko thank you for your response

It depends what you are looking for. Please note that the 13” mbp with an i7 cpu will start the fans much more often than a 15”. At the same time, 13” is much more portable than the other one.

The 13” supports only two monitors simultaneous (internal + external or 2 externals) while the 15” supports more than that (i had 4 at the same time).

Personally i use a maxed out version of the 2015 15” one. My girlfriend uses the 2015 13” maxed out version. Besides the above things, there are some differences in terms of audio output (15” is much better, loader and the sound is not that flat).

From my POV: if you want it as your main dev machine, go for the 15”. Otherwise go for the 13”.

@m0fo thank you for your suggestion, yeah I personally plan to buy the 15" but it is pretty hard to be found here