Having been building my first proper native mobile app this year, testing has played a big part. After every build, my first move is to excitedly take the iPad or iPhone to my little boy, Rudi for some proper testing. It started out quite well, press a few buttons, get a few laughs and smiles...

But as he got more and more acquainted with the device, I quickly found that many of my well thought out UI elements were in fact, far from bomb proof. No, they were proven to not even be baby proof.

They Use Two Hands

It's amazing to me when I watch Rudi on a touch device. It's so natural, it's all about Cause and Effect. I press this, this happens. I liked that, so I'll do it again. If I pressed that and something happens, what if I press some more? Oh, something else happens, I like that... and so on, it's perpetual motion.

But we (adults) all think about it naturally as progressing from the mouse to touch. The 16 month old is not saddled with such archaic notions and instead launches in as mother nature intended. 2 hands, 10 fingers and would be two feet as well, if I don't stop him trying to dance on the retina display.

So, behold, we found that in the Playsongs app, you could actually play multiple songs at once, if with the correct timing, you hit multiple song titles simultaneously. Now, us one-finger one hand adults wouldn't think of that, but the 16 month old, the more button I press, the more stuff happens, well why shouldn't I?

They've Got Little Hands

Little hands, little fingers. The touch-screens really seem to appreciate the digits that probably once belonged to the Bronte Sisters, small and slight, tiny surface area, very precise. Shame they missed out, but my Rudi is flourishing as a result. So much so, that the carefully planned sliding lock element, which locks down the app interface in the song page for when you want to hand the device over to the little cherub, maybe a little fiddly for me to unslide open, but for him, he only needs to sneeze near it and the lock flies open exposing all those nice controls and buttons for him to play with.

The hands tend to be placed in the bottom third, right and left sides, so if you're trying to hide something on the screen, don't put it there - they;ll find it even if they don't mean to. Best is at the top centre, especially on the iPad as it's that much further away...

They Like Real Buttons Too

So, you can put as much thought and well planned execution into the app design, you can lock down the app as much as you like (or as much as Apple will let you) but you can't escape the fact that littl'uns favourite button will be the Home button. Try blocking that off!

And when they find the notifications slider at the top, you're in real trouble too.

So, it's time to think about the hardware - I just bought a TRTL cover for my phone, which enables you to block off the Home Button, will let you know how I get on.

Here's a short video of my little Product Tester, putting an early build though it's paces on the iPad.