For apps that require or have in built support for terminal/scripting Android or Ubuntu Phone.
I rock all my space (galaxy, universe sims etc) on my much more powerful Xeon (12core x 4) rig though wouldn't be surprised if the Motorola Droid / Galaxy S4 could simulate our solar system including a low density asteroid belt and extra solar systems (at much lower estimate aggregate level) in the milky way as far as incoming projectiles are concerned.
Pretty god damn sweet for a phone though I hate it too because of laxing market share in desktop / personal server rig computers.
I've heard of people accessing native terminal on their Galaxy S2/S3 phones though have only used it in an app as emulation that allows root access (if phone is rooted).
For general usage / noob pursuits I find Windows 8 embedded more intuitive for basic UI than Android (or Jellybean GUI).
Apart from mentioning Apple iOS in my 'won't mention them' discalimer, too retard inducing. I had an iPhone 2+3 and it was TOO EASY to the point I got lazy and preferred the 'Google' approach rather than revisiting and practicing my skills.
Windows 8 tries to beat iOS on this though has certain redeeming features like more compatible File Systems on external media than Apple, better app & setting layout etc.
Have Win8+8.1 U-P-G-R-A-Y-E-D-D on 1 of my gaming rigs, love it, hate metro, use desktop.
Though when coming to phone/tablet rooting and advanced back end/command line interface I will always recommend Android (or Ubuntu/Solaris x86 Embedded for applicable compatible models).
Windows CE/XP are also good though (no new roll outs, end support XPemb 2016) programs are often much more aged (WinCE dead) and often not ported if recent to Win7 or 8 embedded.
Sorry if I rambled on/ not prime cuts to chase though feeling passionate about my NEW!!! 20x Raspberry Pi B server.