TP Link mobile power bank of 10400mAh.
Reduced from £24.99 to £16.65 in my local Sainsburys (Cramlington).
It seems to be great so far. Can charge my iPhone and iPad at the same time and the useful LEDs keep track of how much charge is left.
Haven't tried counting the charges on my iPhone from flat yet, but it is next on my list to try out.