I find that tablets have one big advantage over other kinds of cameras: phones, point-and-shoots, and interchangeable lens cameras (like the NEX-5R, which I own).
And that advantage is the size of the screen, which lets me see the photo I'll get before I actually take the photo. Or after I take the photo.
By comparison, the 2.8-inch screen on the NEX, or even the 4-inch screen on the iPhone 5s, don't let me see what kind of photo I will take or have taken. I can zoom in to check for specific issues like blur (caused by camera motion or mis-focus) and ISO noise, but I find it hard to evaluate the composition of the scene as a whole. I have to come back to the computer before I can see it, by which time I may have returned to my country and it's too late to take another photo.
Is there a way in which I can use my tablet to help me compose better photos? I can think of a few:
Take photos on the tablet itself. I'm not in favor of this, given the low quality of tablet cameras compared to the iPhone or the NEX.
Use the tablet to compose the photo, what objects to include and then exclude, and then take the photo on the iPhone or the NEX (which are my primary cameras) instead of on the tablet .
Similar to (2) but take a photo on the tablet AND on the primary camera.
How would you suggest I make use of a tablet to compose better photos? Or are all of these ideas impractical, in which case I should leave the tablet at home and learn composition the hard way: trial-and-error, over time?
 The focal lengths of the iPad, iPhone and my preferred lens on the NEX are all roughly the same: 30mm FF-equivalent.